Modern Vespa

Thought I'd start a thread on my P200 performance build. The goal is to start with a "bolt-on only" build and see how well it works. I want to be able to revert the bike back to stock if I wanted to. By "bolt-on", I mean not splitting the cases. I figure everything else is open for mods. The plan is to build a nice running P200 that I can use to cruise around on and drive to work. By drive to work, I mean hop on the highway and not get run over.

As it sits, my P200 has about 5,600 miles on it. It will happily cruise 55+mph. The bike is currently stock except for a Sito+ and some rejetting. Up until now, everything I have done to it has basically been for maintenance. The bike is a real strong runner so I am approaching this build with a bit of caution. I don't want to take my great running bike and create something that only wants to accelerate or can't run a constant throttle without the risk of blowing up.

With all this in mind, I carefully chose the parts by what I could find used or on sale.... Well kinda.

The build started when I scored a nice used Pinasco kit off of Scoot.net classifieds. From the same seller I also picked up most of a Spaco 24 carb. The Pinasco kit was going to fit my bill nicely since it would basically bolt on a set of stock cases and it was an aluminum cylinder with a Nicasil bore.

I had read constant tales of problems about people setting up Pinasco kits. The general consensus was the heads needed mods and the porting would or would not work with a stock or stroker crank. I found the best way to resolve this was to drop ship the parts from Chicago straight to Hotrod Al in Fresno. Yep, I never even saw the purchase.

Al got my parts in and confirmed that the carb was in good shape and the Pinasco kit was in amazingly good condition and did in fact include a pack of brand new rings. We talked a bit and I described what I wanted to do. We decided to port the cylinder and modify the exhaust, cut the head and convert the carb to a Vortex. I went ahead and shipped him the original airbox. I wanted the top modified for the filter and I wanted the bottom matched to the carb. While I was at it I sent him the flywheel to have lightened.

In the meantime, I convinced a fellow scooter enthusiast to part with his 226 pipe and picked up a banded clutch bell off eBay (sorry if I sniped someone on the forum...). Also picked up a CHT to help in tuning and to reduce the risk of seizure.

So here is the starting point:



Chuck

Awesome set up. When do you plan on installing?

tidy stuff, just remember to do your brakes as well!

Scootalicious goodies you've got there! G/L with your build.

I'll keep an eye/ear (YouTube?) out for this when you're done.

Cheers

Things are off to a slow start. The plan was to start with the clutch. I needed to pull the pipe so I figured I'd do the clutch and yank the pipe while the rear wheel was off.

Turns out the banded basket I got off eBay is crap. The ring they welded on was too small. When the pressed it on the basket to weld it, it bent all the turrets in slightly. Everything looked real nice till I realized a clutch plate wouldn't even fit in the basket. The openings for the tabs on the friction plates were about 14.1mm wide at the bottom and some were only 13.3mm wide at the top. The tabs on the friction disks are like 13.8-13.9mm wide.

I sent a note to the seller and asked for a refund. At least I found out with the parts on the bench. I just pulled the new clutch out of the package and hadn't even soaked the plates yet. I guess I found this especially frustrating after my Cosa experience. I got ahold of one of the "defective" Mercur Cosa clutches where the turrets weren't machined deep enough. I spent 2-3 hours making the cuts in the basket deeper. Only I never did get the clutch not to drag. I did dig into it more and it looked like the steels were warped. After having that clutch in and out of the bike 4-5 times I went back to the stocker.

I figured a simple basket swap on the stock clutch would be the way to go. It's never that simple.... Now do I punt the clutch mods? probably not as its a matter of principle now. Does anyone know anyone in the US that has a banded 7-spring clutch basket?

Chuck

Chuck,

Drag about the bum part.

Scooterwest seems to have the banded clutch basket.

http://www.scooterwest.com/items/?_pageCCS=t#page=/item_details/P-PX-Stella-Reinforced-Clutch-Basket/2293

...or even this option.

http://www.scooterwest.com/items/?_pageCCS=t#page=/item_details/Vinatge-Weld-On-Clutch-Reinforcing-Band/2294

Good luck and keep us updated!

Cheers

Does the top block of the vortex come off so you can get to the jet stacks? Also, how do you mount it as it looks like the second mounting hole is obstructed? Interested in converting a 26si to vortex, so I figure it'd be cool to ask here.

There is a single screw to the left of the idle speed adjustment that holds the block on. You can remove it to gain access to the jets and the front carb mounting bolt. When Al sent it to me, he included the baseline jetting. Hopefully all I need to do is adjust the idle speed, idle mixture and the air screw which controls the main jetting. All the adjustments are accessible with the top on the carb.

Chuck

Pretty cool stuff, but it looks like access to the idle screw is only if you take the carb top off?

All the adjustments are easy to get at. You need to take the airbox lid off to get the mixture screw and the idle speed but once the carb is mounted, you don't have to take the top off of it. Here's a pic of the adjustments.



Hat's off to Dave at ScooterMercato for hooking me up with another banded clutch basket. He just happened to have a SIP basket on the shelf. Which is a good thing since I was eyeing a beautiful MMW machined basket for 3x the price. Looks like I'm back off and running again.

Chuck

now wheres the fun in that .... i remember my 85mph poleposition on drums didnt care a jot ............ id shit mesen now

Finally back to the project. I had a bit of a delay due to some clutch issues. The banded basket I bought off eBay was crap. The guy who put it together made the band too small. When they pressed it on the basket, it bent all the turrets inward. The top of the basket was about 1.7mm smaller than the bottom. Bottom line, there was no way the friction plates would fit let alone the pressure plate. The seller of course said it was my fault since I didn't know how to tweak stuff to make it work.

Needless to say, its headed back to the seller. my guess is, I will be stiffed for return shipping. I believe he's going to relist it so watch out. If you see a banded basket from VS4 aka Tim Stafford, watch out.

Here is everything laid out for the rebuild. The new basket is a SIP SeriePro that I got from Dave at Scootermercato.



I started out with the clutch rebuild since I need to take the rear wheel off to pull the pipe. Since the bike was apart on that side, I figured, start with the clutch. I find it easier to just lay the bike on the right side to do the clutch. Since mine is a bit of a beater, I just yank out an old moving blanket.



Three bolts and the cover is off.



I find it real easy to take the clutch on and off using an impact wrench. This way you don't need a holder. i know that position 2 on my wrench is around 35 ft-lbs.



Only takes a few seconds and the clutch is off. Just make sure you keep an eye on the woodruff key as they tend to walk off.



I made a compressor tool out of some spare hardware that I had in the garage. This is all it takes. It works on both regular and Cosa clutches.



My bike had a little over 5k miles on it. The clutch was in great shape. The thin brass washer was messed up. looks like it was made wrong at the factory. I replaced it with the new one I bought. the bronze bushing seemed fine so I left it.



When I started putting the clutch together I noticed that the pressure plate was hanging up on the band of the new basket slightly.



I went ahead and got out the Dremel tool and ground a little off the ends of the tabs on the pressure plate. Just need to take your time and test fit every couple minutes. I just removed enough to leave a slight bit of clearance between the bands the the end of the tab.



You need to make sure the new springs are seated into the recesses in the pressure plate before you compress the clutch all the way. There is a great page on the Scootermercato site showing how to rebuild the clutch. I got this tip from here:
http://www.scootermercato.com/Garage/Tech-Tips/Large-Frame-Clutch-Rebuild



Done. All back together.



Now it's time to button it all back up. Make sure to bend the tab on the lock washer and be sure your key is in place. Don't need any spare parts in the motor.



When I went to button the cover on, I had problems getting the bolt holes to align. I pulled the cover off and found the band was interfering with a rib in the top of the cover.



A quick grind with the Dremel tool and we were bank on target.



While I was at it, I pulled the pipe off. Looks like we found an oil puddle.



Seems my sight glass was cracked.. again. Well, we will get to that when I pull the gas tank to run the wires for the CHT.



Now back to the working side of the scooter to mock up the top end. I wanted to get a squish measurement to make sure the had and barrel were cut to the number we wanted.



Enough for today...

Chuck

Last edited by chuckactor on Fri Feb 24, 2012 4:19 am; edited 1 time in total

I wanted to mock up the new top end to double check the squish. I knew Al needed to deck the top of the cylinder but I wanted to bolt it up and measure it on the actual motor. I quickly found that you can get the head off but you can't pull the barrel off as it sits.



I have a motorcycle jack so I put it under the bike and removed the rear shock bolt. With the bike raised and the motor tilted down, the cylinder slides right off. I've been tripping over the jack for years now.



Everything looked in pretty decent shape. I did find that the base gasket had a crack in it.



Here are some side by side shots of the stock top-end versus the reworked Pinasco from Al. You can really see the difference in the boost port.



The Pinasco cylinder for the 200 has the transfers in the cylinder and not cut into the cases. Just like a stocker.



In order to make up for the reduced transfer area in the cases, alot of work is done to the piston to compensate. You can see that Al really does alot of work here. Pretty nice shape for a used kit.





The head is recut and the combustion chamber opened up a bit. The stock Pinasco head has a pretty low volume and needs to be modified to work properly.



Here's a shot of the piston at BDC so you can see the ports.



OK. Yeah this is a bit ridiculous. With my old RS125, I used to lay one piece of solder across the top of the piston to measure the clearance. Here, the gap was so big, I had to practically braid a rope to make it work. What I usually do is place a piece of solder on both sides of the wristpin. That way it won't tend to rock the piston in the bore. I stick it to the top of the piston with heavy grease. Put the head on and rotate the motor a couple times. Then you can pull the head off and retrieve the crushed solder.



In this case the gap is huge. With so much solder, its probably not very accurate. I was getting between 3.4mm and 3.5mm of gap. Eek. that won't work. We were shooting for around 1.2mm.



The plan was to take material off the top of the cylinder to compensate for the negative deck height. The goal is to set the piston for zero deck height and have the squish cut into the head. In order to get a good measurement, you need to make sure the cylinder is securely held down. I did this by slipping some sockets over two of the studs and then bolting the cylinder down. By doing this I could use the depth measurement on my calipers. I measured in 4 places around the perimeter of the cylinder and determined the piston was a little over 1.7mm below deck.

To be honest, I will probably bolt it all back together and check one more time. I'll put the top ring on this time and double check. The Pinasco uses an L-shaped top ring. Without the ring on, there is a fair gap between the top edge of the piston and the cylinder wall. I want to make sure the caliper fell correctly on the outer edge of the piston and wasn't getting in the gap. Better safe than sorry you hacked the top off your cylinder.

Sure enough I bolted it all back together and measured again. This time I put the top ring on and switched to my older dial calipers. They have a fatter depth probe. This time I was getting around 55 thousands (1.4mm). I think we'll go with these numbers to be on the safe side. Worst case I can always lap the head down a bit.



I did grab a set of feelers gauges as a sanity check to see where I was. Between 1.5mm and 1.7mm seemed right. When Al puts the cylinder back in the lathe, he is going to cut an o-ring groove in the top.

One option that I want to talk to him about is leaving the cylinder as is and cutting the head so it goes into the bore of the cylinder. This will allow me to go to a stroker later and not throw all the timing numbers way off. If I cut the cylinder, I would need a packing plate later. If we can do the head this way, he will need to add dowel pins to the head to center it as there will only be about 0.3mm protruding into the cylinder.

We decided against this as the edge of the chamber will be small and pretty short. the odds of damaging the lip during assembly is pretty high.

As an FYI, the super high end Seel race cylinders used on the RS125 had the cylinder almost 2-3mm taller than normal and had the combustion chamber recessed way into the top of the cylinder. They did this for detonation reasons. On the RS125's, deto would erode the top edge of the cylinder and perimeter of the head. Copper rings were cut into the top of the cylinder and the perimeter of the head as it didn't get eroded as easily.



I went ahead and took a couple measurements off the head to see where it was at.



The nice part about the Pinasco is that it is close to a bolt on. Mine has had some pretty extensive port work so the boost was opened up a bit. I went ahead and cut the base gasket to match the cylinder and laid it on the cases to see how far off it was. Hmm... pretty big difference. I decided to match the boost port up in the case.



I marked the top surface of the case with a black Sharpie and traced the outline with an Xacto blade.



I jammed the case opening with paper towels and covered the rod up. Everything had a pretty good coating of oil on it so any stray fragments weren't going to go far. I used a cutter on a Dremel with a flex shaft. I cut so it would throw must of the fragments out. To be honest it went real quick and easy. I pulled the towels out and everything looked real clean. If you take your time and make sure everything is plugged up good you should be able to keep the chips out of the case.



So with measurements in hand, the head and barrel head back to Fresno for the final adjustments. I just need to sync with Al on the final plan on how we want to reduce the squish.

Chuck

Last edited by chuckactor on Sun Sep 04, 2011 3:28 pm; edited 1 time in total

the knowledgable folks on this forum amazes me. And you all make it sound as easy as making a cup of coffee. I'm impressed Chuck. Good luck w/ the squish, whatever that is.

Note - In real life this step is out of place. In order to mount the top end on the motor, you need to drop the back of the motor down to tilt it up. If you try to do this with the carb box on it hits the frame. When I went back to put the cylinder on the final time, I had to remove the airbox and carb again.

I sent the cylinder back out to Al to have the top cut a bit and an o-ring groove added as well. In the meantime, I figures I'd throw on the airbox and carb. All pretty straight forward stuff but a couple hiccups none the less.

Here's a pic of the mounting surface on the motor. I just needed to clean off a little of the old gasket off the surface. Make sure to keep the crank positioned so the intake is closed while your working. Dropping a bolt or washer down the intake would be a bummer.



Here's all the parts that are going on. Of course if you look closely, I grabbed the wrong screw to hold the lower airbox onto the case. I guess when you've had it apart for 3 weeks you kinda forget what goes where.



You can see where Al matched the lower airbox up to the carb. You can also see all the minor dinks in the bottom of the slide. I bought the carb used and it looks like whatever motor it was on last exploded. It's really only cosmetic. Any burs have been sanded off.



Here you can see a bit of mismatch between the airbox and the cases. That's going to have to wait until the cases come apart one day. I might grind the boost port area of the cases but the intake is a bit too hard to block off. I'd be launching metal fragments right into the lower rod bearing. So for now we are going to leave this. Looks like I found the correct screw.



It's always good to check things as you go. Here you can see that the Vortex carb is bored out compared to the stock 24. I need to pull the carb back off and trim the opening in the base gasket. You can also see how the air horn on the carb has to come off to get to the mounting bolts. You just need to pull the idle speed screw and one allen bolt.



Make sure you use a torque wrench on the carb bolts. I've heard too many stories about warping carbs and slide binding.



Now to put the top back on the carb and connect up the fuel line. The velocity stack comes right up to the edge of the airbox so I had to trim the top cover gasket away on the side.



And lastly the cover goes on with the original screws. All done.. except for the usually hiccups...



Like the fact the slide won't shut because the throttle cable is hung up somewhere in the headset. I probably pushed the cable inward while working on other things and now it jumped partway off the pulley in the headset. I was hoping not to have to open that up. My ugly but amazingly functional fairing, makes removing the top of the headset a bit harder than usual.

And of course something is binding the fuel line. I barely could pull it back out of the frame enough to get it on. I need to pull the gas and oil tank to see what it's hanging up on. I guess the CHT install will be tomorrow...

Chuck

Last edited by chuckactor on Tue Sep 27, 2011 7:14 am; edited 1 time in total

Not much to do today. It's way to hot to work outside. I went ahead and installed the cylinder head temperature (CHT) gauge and replaced the oil sight glass. The CHT is from Trail Tech. It is model ET3 for a 14mm sparkplug. The are only $40 so it's a nice cheap piece of insurance. For the money, cylinder head temperature gauges are nice to have. They aren't fast to react so they won't catch rapid changes in engine temp. They will give you more of a steady state idea of what is going on. To really see what is happening you need to use an exhaust temperature gauge. They react quicker to what is going on with the motor. I had one on my RS125 racebike for awhile. It was neat but to be honest I was too busy riding to watch the temp gauge. For cruising down the highway to work, this will be just fine.

You can order a 4' extension cable for the CHT from Trail tech for $10. I decided to just cut and splice the cable to make it longer. if you have a soldering iron and some heat-shrink tubing it can save you a few bucks.

I cut the wire near the connector and soldered in about 5 feet of wire I scavenged from a power supply. I decided to mount the display up on top of the glovebox. I used a stiff piece of wire to fish the lead through the grommet from the turn signal inside the glovebox to the horncast. Next I used a wire snake to pull the wire from the horncast area....



...to the area under the gas tank.



I used the existing grommet for the electrical cables to run the remaining wire from the sensor lead to the gastank area.



Next I soldered the tww wires together under the tank. I used heat-shrink on each wire and a third piece over the two connections to try to keep the crud out.



I went ahead and put the plastic piece in under the tank to seal off the tunnel area and replaced the sight glass. Sure enough there was oil everywhere. It must have been broken for awhile as I had a spare in my parts box and I can't remember ordering it.



Here's a shot of the wire going in to the grommet inside the glovebox and looping up out the top to the gauge. The picture should be rotated 90 degrees clockwise. So tilt your head to the left while viewing.



And lastly here is the finished product. You can see that I used the included double back tape to attach the display. The other option is to use a couple sheet metal screws but then I'd have to drill holes in my pristine bodywork.



Chuck

Last edited by chuckactor on Mon Sep 12, 2011 10:05 pm; edited 1 time in total

Thank you for posting.

Your welcome. I was beginning to think I was the only one reading it.

Chuck

Im following! I just dont have an older Vespa so I have nothing to interject, but its facinating, really. I'd love to have the time/space to do this sort of thing. Keep up the good work!

Awesome job here. Thanks for posting all the detail. I LOVE this kind of stuff.

This is a watched thread for me. I'm very interested because this is the set up I want to do for my P200. Looking forward to seeing it run soon.

Really enjoying the thread. I need a lot more experience before I would try it though it would be great. Apparently I cant even install seals properly..

I'll get my shot at the seals soon enough. I did a flywheel seal already but the clutch side is original. it seemed to leak a little based on the smell of the oil but after riding it, it "sealed" up fine. Al is making me a cut and flowed crank with a Yamaha rod. I'll get to the in a little while. right now I really want to get the bike back together.

Got a tracking number for my cylinder and head but they aren't schedule to be delivered till next Tuesday. Al cut 50 thousands off the top and cut it for an O-ring groove. Hopefully the clearances are right. The only thing left to do now are find out why the throttle cable is bound. The slide is hung half way open with the throttle closed. It feels good it just goes from 1/2 to wide open throttle...

Hmm... I replaced the slide link rod in the carb. The original was for a non oil injected carb. I wonder if there are different length versions? I guess I need to compare it against the 24mm i took off before i start disassembling my headset.

Chuck

Scooter is all up and running now. Of course I'm behind on the write up so you'll have to stay in suspense for a bit. When we last left off, I was waiting for the cylinder to be cut and I had a problem with the slide hanging up.



My first though was that the throttle cable had somehow gotten bound up in the headset. So I went ahead and disassembled it. Not a big deal except my bike has one of those super ugly period fairings that I needed to take off. So I got that all done and went about pulling the 4 screws holding the headset on. Of course when I got to the very last screw, I noticed the bushing that guides the throttle cable into the headset was out of place. Yep all I had to do was poke it back in with a screw driver. I didn't need to take anything apart. Ugh... need to slow down a bit and look for obvious stuff.



When I first got the head back I screwed a plug in to see how it seated. I remember seeing an early post of a Pinasco kit that Al did for a guy in Singapore and the tip of the plug protruded into the combustion chamber. This was do to the amount that the chamber was enlarged to reduce the compression. Sure enough, mine did the same.



At first I was annoyed till I realized I was using the CHT. Normally you remove the sealing washer from your spark plug when you use a CHT to make up for the sensor thickness. In this case, I'd just leave the spark plug as-is.



And now the plug depth is good w/o having to use additional washers etc.



Here's a picture of the top of the cylinder after I got it back. Al cut 1.25mm off the top and added an O-ring.



I'll be honest, I didn't re-measure the squish after assembly. I knew it was was big to start with and to be honest, it probably could have been cut another 0.5mm or so. I'm guessing the squish ended up at about 1.8mm or so. I could have left out the base gasket and compensated but I didn't feel liking heading to the dealer to pick up some Yamabond to seal the base of the cylinder. At this point, I just wanted to get the bike together and running

Chuck

Before you put the cylinder on it's good to check the ring gap. You do this by inserting the rings into the cylinder. You can use the piston to press them in and make sure they are square to the bore. The Pinasco kit does not come with any recommended guidelines. I used the following rule of thumb:

Stock Motor - 0.004" gap per inch of bore
High Performance Motor - 0.005" gap per inch of bore

Just multiply the bore diameter in inches (2.72") by the guideline. For my application, I'm going to assume high performance. This makes the gap work out to around 0.014". The stock ring gap measured around 0.009". I used a small flat file to adjust the gap of the rings. If you want to spend some more time with a file, you can use a round file to round the edges of the ring end that goes against the locating pin in the piston. This is an old racing trick. The idea is to keep the sharp edge of the ring from rubbing against the piston ring pin and working it out of the top of the piston. If that tiny little pin falls out then the ring is free to rotate. Usually it will rotate around until the ends of the ring are inside one of the ports. At this point the ring jams in the port and all hell breaks loose...



I tried to install the piston on the rod and then slide the cylinder over it. This turned out to be a pain since the bottom of the skirt on the Vespa cylinder is straight across with no cutouts and the pin for the second ring is lined up so the ring gap is on the blind side of the piston. After farting around for a couple minutes, I pulled the piston and installed it into the cylinder off the bike.



Then you can slide the whole assembly on and install the wrist pin. One tip is to install the circlips for the wrist-pin with the squared edge toward the outside. if you look at the circlips, one side is rounded from stamping them out and the other side is sharper. Always install the sharper edge toward the outside surface. Make sure you lube everything with some 2-stroke oil during assembly.



I decided to go an install the pipe next.



Here's a shot from the bottom so you can see how the 226 pipe fits.



I had to drill holes in the fins for the exhaust springs. I just drilled a hole from the top down through 4-5 fins till I got the hole where I wanted. the holes are kinda big but I needed room to hook the springs on.



Here is what it looks like from the side.



I should have checked the pipe over closer prior to the install. 226 was super nice and sent me some new sticker for the pipe. What I should have done is check the O-rings. The pipe uses Viton O-rings between the header and the exhaust stub and the header and the chamber body. Turns out both of the O-rings were shot. I will go ahead and order some new ones but will install as is for now.





Here is the one tool that you must have to install exhaust springs. Spend the 10 bucks and buy one. I think this is one from Motion Pro. Don't try needle nose pliers or vice grips. It is a bear. With the correct tool, it is a 5 second job to install and remove the springs.



Here is the pipe mounted. The outer spring on the exhaust stub seems stretched a bit far. I'll probably order a slightly longer one.



You wonder why 226 sells an $18.50 shock bolt? Here is why. In order to install the back pipe mount, you need to ditch the lock washer to make room. You can see it barely fits as-is. Make sure you use Loctite on the nut! If you had an aftermarket shock that was aluminum, it would never work.



I thought I'd be smart and surf the net to find a "cheap" 9mm bolt.... Good luck! There are probably 4-5 applications in the world that use 9mm bolts. They flat don't exist except for some rod bolts and I think some weird Yamaha cylinder bolts. Guess I'll be ordering one from 226 along with my new O-rings. Next up was the silencer.



Chuck

Last edited by chuckactor on Tue May 31, 2016 12:42 pm; edited 1 time in total

The next step on the install was to set the timing. Al recommended that I run the timing at 18deg Before Top Dead Center (BTDC). Stock is 23deg. The www.scooterhelp.com website has alot of great information on setting timing on a Vespa motor. Take some time and review the information here:

http://www.scooterhelp.com/tuning/vespa.malossi210.install.html#timing

I decided to use the piston height measurement method instead of using a degree wheel. I happened to have a dial micrometer timing gauge. I just needed to make a mount to use it on the Vespa motor. My previous race bike had a centrally located plug so I could just screw the timing gauge straight into the head. The spark plug hole on the Vespa is angled so you need to make a holder to position the gauge parallel to the piston travel. Here is the setup I used. The holder was made out of a 4" mending strip from the Home depot. I enlarged the end holes and then drilled a 1/2' hole in the middle and tapped threads using a spark plug thread chaser tool. Not really a tap but it worked good enough. It would have been easier if I had a drill bit slightly bigger than 1/2"...



Here's a pic of the timing gauge setup I used.



The scooterhelp website has a page with a simple calculator to convert the crank degrees into piston position.

http://www.scooterhelp.com/tips/timing/timing.calc.html

I used a casting line on the crank case as a Top Dead Center (TDC) mark, I went ahead and marked a position for 18, 20 and 23 degrees Before Top Dead Center. According to the calculator, the piston position at the various crank positions (57mm stroke and 110mm rod).

18deg - 1.75mm
20deg - 2.15mm
23deg - 2.83mm

Since my timing gauge reads out in 0.01mm increments, it's a piece of cake.



I had just taken the flywheel off for this picture to move the stator slightly to retard the timing. There is just one Sharpie mark on the flywheel that I made to line up with the TDC mark on the case. Here are a couple pics of the lightweight flywheel that I got from Al.





Jumping ahead a bit.. I must say I'm a big fan of the lightened flywheel. The bike seems to shift much smoother now. The RPM drops a bit faster between shifts and seems to allow me to engage a higher gear smoother than before. Definitely a good deal for the money.

I took a guess on the new stator position. With the Vespa, you need to take the flywheel on and off to check the timing and adjust it. I believe I read that each degree of timing is approximately 1mm on the stator. Well I rotated the stator back about 5mm and then put the flywheel back on and grabbed a timing light.



The timing light is a self-powered (battery) Flaming River light (http://www.flamingriver.com/index.php/products/timinglights/FR1001) I got used off eBay. You just connect the one lead on the plug wire and press the button. It's not the brightest light in the world but it sure is simple and convenient. Especially if you have a bike with no battery. Some how I got lucky and nailed 18deg on the nose the first try. Make sure you connect the ground wire on the CDI when you start the motor. Normally it is under one of the shroud screws.

Then it was just a matter of buttoning everything up.



Chuck

Last edited by chuckactor on Fri Feb 24, 2012 4:22 am; edited 2 times in total

Hey Chuck, you look like a real pro in this sphere! Very nice project, keeping an eye on it! Nice work and good luck

wow, yet another calculator on scooterhelp that I had no idea existed, very cool. I had put together one to do a range of deg>positions in a table (useful for port timing as well).

http://blog.oopsclunkthud.com/tuning/PistonPosition.php

Great writeup on the bike as well.

Patrick thanks for the links!

I guess people are wondering how the bike is running. I've actually only had it out a couple times so far. Its been rainy here and I've just been busy. Let's see if I can recall the details.

The bike actually fired right up. It didn't start on the first or second kick. Not because of any tuning issues but because I was wearing flip flops. To say the bike has a bit more compression is an understatement. After a couple kicks I decided a set of real shoes was in order. Remember, everything was oiled up so the compression was perfect. Rather than risk destroying my ankle I decided to slow down and proceed with caution. Its not crazy compression, just alot more than stock. I measured 155 PSI when I threw a compression tester on it.

Anyway, the bike start right up and I threw the timing light on it and verified I was at 18 degrees as planned. The carb adjustments are pretty straight forward. I adjusted the idle speed and went let the bike warm up to about 200 deg on the CHT. After that I let it cool down and then heat cycled it again. The top end was used the bore clearance was good. It did have a new set of rings though. My background with 2-strokes was racing RS125's. Breaking in a new top end was 2 or 3 heat cycles and then one slow lap. I find it interesting listening to people talk about breaking in a top end for 500 miles. I'm used to tossing in a new ring after the weekend (100 miles) and new piston every other weekend. I decided it was good enough for a quick ride.

I started with the air corrector screw all the way in (full rich) and the idle mixture out about 3 turns. I buzzed up and down the street and stopped every 100 yards to week the idle mixture. It was bogging bad so I would stop and turn it in a 1/4 turn and try again until it took off cleanly. Next I started using more throttle and feeling the upper end of the rev range. It was not revving out clean so I would stop and unscrew the air corrector screw about an 1/8 of a turn at a time until it revved clean. As you open the air corrector, you lean the mid-range and top end.

After annoying the neighbors for about 15 minutes it was time to venture outside the neighborhood. The bike is alot louder than it was with the Sito+. Not crazy but definitely dirt-bike like. You can definitely tell you have a pipe on the bike. While a stocker drones along, this thing now has an on and off the pipe mode. A quick run down the road has shown a whole different character to the bike. It no longer is a tractor. It likes to rev and stretch its legs. Boy it accelerates alot harder than stock. Try to ride it at part throttle doesn't work so well. To be honest, I'm still trying to get it right. Mid throttle to full throttle works great.

Anyway, after cruising around for another half hour or so I was drawn to I-95. The bike quickly accelerated up to the speed of traffic. What the heck, I decided to open it up. That's when things got scary. I only had the Vespa on the highway a couple times before. But get it over 60 for an extended period and it started to develop this tail wag. Literally the bike would start to develop what at first felt like a high speed wobble. It felt like the back end of the bike was going side to side a couple inches. It didn't get worse and the amplitude stayed the same. Very un-nerving as you are scooting along on 10" wheels and a 34 year old bike.

The CHT looked good so I decided to open it up. I got into it for about a mile or so. I was basically watching the head temperature and decided to back off as it headed up to almost 400 degrees. The motor felt good but it was still wobbling and I was nervous running it so hot with very few miles on it. I exited and stopped for a quick adjustment. The Vortex is super simple to adjust. I screwed the air corrector in a 1/4 turn and headed back to the highway. The 1/4 turn dropped the CHT down to about 355 deg. It was cooler but the top end felt flat. In actuality it only lost about 3 mph.

When I got home I checked the GPS and it showed a speed of 73 mph. Not huge but until I get the wobble fixed, faster than I want to go. My guess is that the huge fairing on the bike might be causing it. Or perhaps the front end in need of adjustment or the worn engine bushings. I'll start with the fairing first to see how that goes.

Chuck

I'd try upping another pt or two on the main jet.

what tires are you running on the bike? might want to upgrade if you plan on doing speeds over 60.

The bike has a new set of Michelin S1's on it. So those should work OK. The cool part of the Vortex is no main jet changes. There is a main jet but it is drilled out to some huge size. I don't have my notes but I think I stuck a pin gauge in it and it measured 0.071" (1.8mm). Does this mean its a 180 main? I know from running with the air screw all the way in (full rich), that this jet is plenty big. I think the farthest I had to open the screw is around 1-1/4 turns so far.

The air corrector screw gives the bike an adjustable main. With the air screw all the way in, no air is bled to the jet stack. As you unscrew the air screw, it bleeds air into the jet stack and leans the mixture. You can just pull back the foam on the cover and get to the screw with a ball headed allen wrench. So I just drive around with a small slotted screw driver and a 3/32" allen in my pocket to make adjustments. You just pull the side cover off to get to the carb. No need to remove anything else.

On my last ride, I noticed the ground wire had broken off the CDI. I had actually fixed this once before. Seems all the old copper turns to dust after awhile. The bike ran OK and a quick check on line confirmed that the ground wire is redundant. Being anal and all, I had to fix it anyway. Replacement CDI's are pretty cheap but I decided to see what I could do.

I took a Dremel and started digging into the potting material on the CDI. About 1/4' down, I found the end of the wire and carved the plastic and insulation out from around it. I then soldered a new ground wire to it and filled the cavity with 5 minute epoxy.



Hard to see in the picture but I try to use tin plated copper wire. It is alot more durable than standard copper wire and really resists corrosion alot better. Here in Florida its easy to find because its the standard for marine applications (at least on decent boats). If your going through the trouble of replacing the green wire of death or other parts of the scooter, look for tin-plated stranded wire. Costs more but it's better to do it right the first time.

Chuck

Last edited by chuckactor on Thu Nov 10, 2011 6:09 pm; edited 1 time in total

After all this time and effort I have literally riden the scooter 2 times. Between the rain, kids I just haven't had the time to mess with it. Part of the issue is the noise. By the time I get around to it, it's late and I don't want to piss the neighbors off.

The other issue is that I am in the no fun tuning stage of the build. The scooter runs great from 1/2 throttle up but has been running like... well, shit on the bottom end. Part throttle just doesn't work. My first reaction was that I took a perfectly good Vespa, dropped a grand on it and made it un-rideable. I assumed the porting and the pipe just changed the whole character of the bike. It was not going to run right for just cruising around and that was the bottom line. No more cruising down the beach.

I decided to take it out last night after dinner and tweak the carb some more. I tried one-turn out on the mixture screw, 2-turns, 3- turns, 4-turns... No big difference. The bike still ran crappy... unless you rolled the throttle all the way open.

I pulled over and parked the bike and turned the idle speed up pretty high. At this point I turned the idle mixture (or maybe its really the "low-end" mixture screw) all the way in. Then I slowly screwed it out and listened for changes in the engine. Nothing.... I screwed it all the way in and took it for a ride. The bike rode the same. It should have been super lean at part throttle yet it was still acting like it was rich.

I had an idea but I had to head home and swap carbs to test my theory. I still had the original 24mm carb sitting in a box. I decided to keep the original carb to use on my PX150. Glad I did.

I went home and swapped carbs. I left the jetting in the original carb exactly like it was (55/160, 160-BE3-118). I pulled out of the driveway and the bike had part throttle performance. I could ride around my neighborhood at 1/4 throttle and it ran pretty good. Needed some tweaks but it now had a carb that worked at part throttle. I buzzed out of the neighborhood and got on it a bit. Felt good but it fell on its face and detonated like crazy at high revs. I kinda expected that since the main jet was probably 10 sizes to small. But I was on to something....

Chuck

Wouldn't be the first.

Yeah the tuning part sucks.

Could need a bigger/more adjustable carburetor?

It was becoming obvious that the low-end circuit of the carb was not working right. I had suspected it had something to do with the mods Al made to the idle mixture screw. Al shortens them and changes the taper to make them more aggressive. Here's a pic of the modified one:



Something in the carb was letting it dump fuel at the low-end even with the mixture screw all the way in. I went ahead and screwed the idle mixture screw in all the way and examined it under a microscope. You guys have microscopes in your tool box...right?



When you screw the idle mixture in all the way it should shut the fuel off. In my case, it bottomed the spring out before the taper of the screw bottomed against the carb body. In this picture you can see that the taper still has a gap between the screw and the carb passage. Basically it acts like it is screwed out even when it is screwed all the way in.



To verify this, I removed the spring and screwed the mixture screw back in. In this case, you can see how the taper of the screw seals against the fuel passage.



When I spoke to Al he suggested cutting a coil off the spring to shorten it. I actually found a reference to this same issue with a Vortex on the web. Someone said a E version carb had a shorter spring to use. When I get home I'll try taking a spin around the block with the spring off the screw so I can try leaning it out. Now that I ran with a stock carb, I know what to expect for the part throttle performance. I'll let you know how it works outs.

Chuck

I think the thing with those Vortexs is to ditch the adjustable air corrector and tune with the fixed ones. Also, the air filter directly over the carb inlet tends to catch the spitback fuel, making the lowend choppy. I universally removed the stock airfilter on tuned largeframes and went with a Unipod style that fit just inside the standard airbox opening. I suggest trying that.

In all honesty, this is the best thread I have read on MV in a long time, if not ever.

Great kit, knowledge, feedback on adjustments, etc.

I love this pipe & the setup is exactly the info I was looking for & can be applied to anyone upgrading thier kit.

Well done!

Well the carb is fixed and back on the bike. I took off for a short run and the bike felt pretty good. Not great but OK. I rode about 4-5 miles to warm it up. I pulled over to tweak the carb and the idle started to come up. I blipped the throttle and it fell back down. Hmm... the idle was moving around a bit the other day. Anyway went off again and then stopped after a mile for another adjustment. Idle racing. So back home I went. When I stopped the idle was racing.

Seems I have a bad air leak. Might be the carb but I'm not that optimistic. We are talking a 34 year old bike with 5,700 miles on it, an original clutch side seal that had sat for a couple years. I replaced the flywheel side seal when I did the stator rewire last year. My guess is the latest blasts to over 7k RPM have finally done the crank seal in.

I'll check the gear box oil tonight. I had smelled gas in it in the past but chose to pretend I didn't since the bike was running great. So for now it will sit. I don't want to hole my new piston.

I did call Al and he's going to build me a crank and make a crank puller for me. So I guess the next updates may get a little further into the motor.

Chuck

Going performance and not changing out seals was asking for a problemo, brother. Don't let it sit, the last thing you want to do is have that clutch side seal blow up and take out your top end.

Change out that crank

Any updates?