Modern Vespa

At the beginning was a small piaggio Zip 50 4t.
I wanted more power and the malossi 80cc kit was not enough for me.
So,i bought a wrecked Et4 150 cc and i started to make an engine swap.

poor vespa!


undressing her


electrical harness on the ground


bye-bye vespa!

I did a check on it


and i found that everything was okay


some primer before paint




and i started to undress my Zip 50

The project was ready






but the power was again NOT ENOUGH!

The camshaft
Looking for BIG HP i tried to buy a hotcam from vespa-soho but they didn't have international shipping so i decided to reprofile my oem camshaft.
First i had to make some measurements by putting the camshaft in this computer controlled test stand for Cam Lobe Measurements.

As you can see the intake lobe at 1,25mm-0,050" lift has 223,86 degrees duration and 7,1541 peak valve lift.
Americans count duration at 0,050" lift and europeans at 1mm lift.

Now you can see the table of the reprofiled intake lobe.
It has been tested before on a Honda Cbr 125 with good results.
Intake and exhaust lobes have been reprofiled the same.
It's not something extreme, 11 degrees more duration at 1,25mm lift and 0,6mm more peak lift,because i don't want to play with stronger aftermarket valve springs.I had some bad experiences with them at the past.

For reference,an air-cooled,2valve similar japan engine of a Honda XR200R has camshaft with 221 degrees of duration and 7,11 peak valve lift.

After milling around the cam lobes i gave the camshaft for nitriding.
from the webcam website:
Gas nitriding is a surface heat treatment which leaves a hard case on the surface of the cam. This hard case is typically twice the hardness of the core material up to .010" deep. This process is accomplished by placing the cam into a sealed chamber that is heated to approximately 950 degrees F and filled with ammonia gas. At this temperature a chemical reaction occurs between the ammonia and the cam metal to form ferrous nitride on the surface of the cam. During this reaction, diffusion of the ferrous-nitride into the cam occurs which leads to the approximate .010" case depth. The ferrous-nitride is a ceramic compound which accounts for its hardness. It also has some lubricity when sliding against other parts.

on the right the factory camshaft


The camshaft after reprofile and nitriding:

Valve job


Of course,camshaft is not enough for stage 2.
I installed 1mm bigger valves from chrome-nickel steel to make it easier for the engine to breath.

I placed the factory valves on the bigger ones to show you the difference in diameter.

Stay tuned,Big Stuff for the little scooter!

Good stuff. Keep it coming.

I decided long ago to buy an original Piaggio cylinder piston set from Liberty 200.
It has 2mm bigger diameter than Malossi's cylinder and it is much cheaper:154 euros when malossi costs about 300 euros!
Unfortunately it was not available at local shops for many months and Easy parts company returned my order back after some weeks of waiting.
Now it is avalable but i have already bought a Malossi kit.

Liberty 200 cylinder swap is a common modification and i have friends that have been satisfied with it.
All air-cooled leader engines(125-150-200cc) have the same cylinder head and camshaft so this is not a problem.

After valve job,i was worried about valve seals so i decided to change them myself to prevent leakage.
It is easy and cheap to change them and i took some pics of my work.

Compress valve springs with that tool


remove half cones with a magnet(red at the photo)


remove upper cup and valve spring


now you are ready to pull the seal,it's easy.


push the new seal on the valve guide.
You are ready!


If you can't find a valve spring compressor,try the caveman way.



It sounds wild, but it works great.. Take a deep well socket that is the same diameter as the valve spring cap and put it on the valve with the square end up. With it centered and square on the valve spring keeper cap, hit it sharply, but not too hard, with a hammer. The two valve keepers will fall out and you can take the spring cap and springs off the end of the valve. This sounds quite radical, but it works great, and if done right will not hurt anything. If you are uncomfortable with this, use the valve spring compressor.
http://www.dansmc.com/valve.htm

Big bore
Old 150cc cylinder and head on the left,specials on the right.



Some pics of the big bore kit installation.

The piston



cylinder assy



I gave some revolutions to the crankshaft to be sure that there was no contact from piston to valves.

Great thread! Keep it coming, please.

Next step:
The CarburetorS



I tested not one,not two,not three but four carbs!
The fourth carburetor that you don't see at the photo is the winner,i keep it for a suprise ending.

As you see at the picture there are 3 totally different types of carburetors.
On the left is a vacuum type Keihin-walbro CVK26mm(factory equipment) with acceleration pump .
In the middle is a genuine round slide Keihin Japan PE28mm.
On the right is the famous racing flat slide Keihin FCR28mm,horizontal-not downdraft edition with acceleration pump.

Factory Keihin Walbro was running good at all rpm range except idle,maybe because of the camshaft.
Turn in-out the pilot screw had no effect,i had to change the pilot jet from #35 to a SMALLER,maybe #32.
The pilot jet seems like a keihin but it isn't,it was difficult to find one.
Anyway i let it die cause i don't like Constant Velocity carburetor's response.

Keihin PE28 Japan
This carburetor is very popular between motorcycle enthusiasts.
You can easily find the differences from the copies,Keihin logo written by fat letters at the sides and there is a big hex screw at the bottom of the bowl for fast pilot and main jet changing.

I was sure that it would be a plug and play solution.But it wasn't.
After several changes of expensive needles and jets,i put it on the self of my garage because i've found something better.

best set up
pilot jet=37
main jet=145
needle=jfn #4

I used a DNA filter pod,great quality product/49mm diameter

Keihin FCR28



This carb is really big and i had to make an aluminium 5cm spacer to avoid contact with the cylinder.
30.000+psi of waterjet cutting machine gave me the piece of the photo at the shape of the intake manifold's gasket.

very nice work!

I've had my eye on the FCR for quite a while, interested to know how that works out.

The throttle response with this carb was excellent because of acceleration pump and flat slide.
At high rpm i didn't noticed any difference with PE28,maybe because they have the same venturi diameter.

But i had 2 problems that sent this carb to my garage's self too.
1.Because of the big size,i could't have the cap at the useful basket under the seat.
2.THE NOISE of the intake at full open throttle.
I could not make it work with any kind of filter except it's red pod.
The noise was terrible,maybe cause the room under the seat acts like a megaphone. It was louder than the akrapovik 4-2-1 of my supercharged Kawasaki Z1000!
So,goodbye FCR.

Not to put a downer on this topic as it's a real good one, but looking for more power by tuning a 4T motor is a waste of time, you have to spend a lot amount of money for tiny gains in power, seen it done SO many times and to be honest it aint worth it. Also the thing is from looking at this topic you are putting real time and effort in which is great with some nice parts going in to match, it's just a shame you aint doing that on a 2T lump as that is what that scooter is screaming out for.

What you should of done if anything was find a 2T lump from a typhoon or an old skipper 125cc then tune that as you can get massive gains power wise for next to no money and the air cooled lump from them lasts forever.

But either way it's a good project you have going on, good luck

The extension on the intake for the FCR may help with the other carbs as well. The intake on vespa engines tends to be way to short for max power. The nice thing about the FCR is you can change out the bell to change the tuned length.

Good to see some interest in tuning the 150 beyond the standard bolt on stuff!
The 2T swaps posted here are neat and I like this effort as well. Thank you!

This thread,is fantastic.. please combe back and continue... Great carb info.. I had tried to get a Keihin cvk32 to work with a kitted lml 2steoke motor I was building.. I knew the carb wouldn't have the quick, racy throttle respone I'm used to, but it was going to be a cruiser... Anyway, I'd never tried before and the guy I was working with had convinced me that the vent tube on the carb needed to be connected to my reedblock (where I normally connect my fuel pump) Without doing my own research I threw out common sense and trusted him, and of course it would not work.. And I know why.. only I learned all the information After I sold the carb on ebay.. I learned a valuable lesson during that project... I'm sorry to be ranting on here, but I find your exploration of carbs very cool. So.. please coninue, you have another viewer.

The gas nitriding is top stuff. It looks like you have a lot of great resorces where you are.. Fun X 100!
Keep up the cool work.
Cheers.

I love the power curve of two stroke engines!!
But i can't stand anymore their smell. I made some thoughts about downdraft Keihin FCR28mm to earn some room and maybe better dyno results.
The intake manifold of the leader engine as you know,has a strange square shape(photo) and i didn't found something aftermarket special.
I had to make myself a billet piece using CNC and then connect a rubber hose on that,to prevent vibrations and heat transfer.

I almost had the solution.
A rubber intake from a Yamaha XT600 as you see at the picture.The problem is the giant step between it's round end and the square shape of the cylinder head's port.
Anyway i gave it up again because in between i found my carb.

And the winner is:
The el cheapo(60$ shipped) Honda Keihin PE 28 from Thailand!
http://carburetor-online.com/
ebay.com


After installing it and pushing the start button i knew that the thai carb would run well with my engine.
Perfect idle,good throttle response,no overflowing,without cough or stumbling.
It is made from Honda Thailand as the seller says at his ebay site but i am not sure for this because the slide,needle,main and pilot jets are not interchangeable with those from my genuine Japan Keihin PE28.I have read that Honda Nsr150 two stroke model uses this carburetor.
Don't forget to order it with the remote choke bowden cable kit for easy operation without opening the engine cover.




I had to change the clip position of the needle and the main jet from #115 to #140.

My final setup(i have modificated camshaft,bigger valves):
Pilot jet #45
Main jet #130
Needle=1550(i dont know what this means,i think it is not Keihin symbols)
clip position=second position from top
Pilot screw=1&3/4 turns from closed position
DNA filter pod 49mm neck's diameter
http://www.e-dnafilters.com/Product.asp?ID=768








I have to say that the set up of the several carburetors took me a lot of time,i installed and unistalled them over 30 times and i spent enough money because Keihin parts are expensive.

The Exhaust



I bought from ebay a sito plus exhaust because i like the shape of the original and i have read that is quiet enough at low rpm.
I know that it isn't a performance exhaust but this is not my problem:The problem is that the stupid,crappy thing doesn't fit!
Now i have to dremel grind the holes of the screws or cut the pipe and weld it again or bend the pipe or....
I am very unhappy.

That's a common problem with the Sito+ (I had one; mine fit reasonably well). The other problems include a propensity to rust and a crummy chromed plastic heat shield that starts to deteriorate after a few months. You can re-use your stainless Vespa shield on the Sito, but the hole spacing will be slightly off. With a little Dremel work and rubber grommets, I was able to make it work.

Why can't they just match the pipe they're trying to emulate? (I know just a vent) but damn... it's like building a ship and leaving off the compass. (strange analogy? maybe, but my point is, they go through all the trouble and then can't line up a couple holes, or have a bend move over a few mm's). Just seems an unnecessary drag.

Transmission

Before installing the pollini upgear kit i changed the five gearbox bearings and the 2 oil seals.I found two of them in not so perfect condition and they are cheap enough to make me buy all of them.

I pushed out the 2 seals with a screwdriver




then it was easy to push the 2 big bearings out with a socket and a hammer after heating the case with a heat gun.
One big bearing is on the wheel axle and one on the clutch axle.




I used this tool to pull out the 3 small bearings








To install the new bearings,i used the method:"hot case,cold bearing"
if you don't have a bearing extractor you can use grease and the HYDRAYLIC EFFECT!
Must see video:
edited to make video embedded (removed url tags) - jimc

This is the polini upgear kit,it includes clutch shaft and the big sprocket from the intermediate shaft.



You can see the difference between the sprockets of the intermediate shaft


I had to press out the sprocket at a machinery


But it was not enough.
The gearing was tall for me and i found (thanks oopsclunkthud!) that i had to change the secondary transmission with that from et4 125.
The secondary transmittion is the wheel axle-driven shaft and THE %$%$% INTERMEDIATE SHAFT.So i pressed out again the big polini sprocket and i pressed it in the intermediate axle from the 125 that i bought from ebay.
Now everything runs fine.


All the stuff you need.Nothing lefts from the 150cc transmittion.

Just love this tread.

Wanted to ask about the Liberty 200 cylinder as an alternative to the 190 kit. Is it really a straight drop in, or are there any mod required?

At half the price of the Malossi kit I can't understand why I can't find more references to this alternative upgrade on the web.

Look forward to reading more on your project.

Liberty 200 cylinder kit is a straight and several times tested swap for Leader 125 and Leader 150cc engine as well.
The 200 c.c. model replaced the 150 cc former version of the Liberty in 2004. In 2009 it was replaced by the ...Liberty 150.

Good factory quality for this kit,great price,cheap spare parts and two more mm of piston diameter than malossi's kit.
Cylinder is made from cast iron,not aluminium as malossi does but do you believe this is a problem?


Cylinder head,camshaft,valves,rocking levers,carburetor,jetting of the carburetor,air filter and filter box remain the same.
This cylinder kit comes from piaggio in a box and includes cylinder,piston,piston pin,circlips for pin and piston rings.
You'll need to buy extra a cheap gasket between cylinder-crankcase and a cylinder head's gasket.

You have to know that the torque will increase a lot,and maybe you''ll need a taller gearing then.
But this is the same problem for all big bore kits.

Piaggio kit,OEM Part Number:844113
Click the links for prices,please:

ebay.it seller

scooter-center

easyparts

piaggiospares.co.uk








Malossi kit

Clutch springs


I had no problem after installing the upgear kit with factory variator and clutch but i was curious to try the stronger red malossi spings for better launches.
At the same time i installed malossi variator with light 9gr rollers from the kit and the result was ridiculous.
The engine behaved like a 50cc,2 stroke.The scooter started to move like a screaming female and was running at high rpm all the time.

So i changed the red springs with the yellow ones from the kit.
They are much softer and now the bike starts to move at the right rpm,not too low as factory springs do and not too high as malossi red spings.







Be careful,i had some thermal fatigue on the clutch shoes with the red clutch springs.

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Variator


I bought and installed a Malossi Multivar system.
The kit includes half driving pulley,ramp plate,shaft,sliding blocks,white contra spring of driven pulley and 2 sets of rollers: one of 9 gr. for 125cc model and one of 12,5 gr for the 150cc.

You can see that there is no difference at the dimensions of the two variators.





But there is a difference at the roller's ramps.Malossi is on the right.




Piaggio variator's axial hole




For their variator,malossi says absolutely do not use lubricating grease.




You must install the white contra spring of the kit for the proper operation of this variator.




Finally there is a small improvement of the whole gearing but i am not a fan of variator swap.Vespa et4 has a good one as it comes from the factory and if you want to change something big,it's better to buy a liberty 200 cylinder kit,the cost is about the same.


EDIT:20/5/2015
After 21.000 kilometers of use,the central axle(Sliding BUSHING) seems to be seized to the pulleys's housing.Look at page 6 of this thread.

Tip:
If you install the Thai Keihin PE 28,it's better to cut a piece 2,5x6cm of the black plastic cooling shroud to avoid contact with the new carb.
Then you can put a small piece of neopren or something similar soft,gasoline and heat resistance material between the bottom of the carb and the shroud to support the weight of the keihin and filter pod and extend the life of the rubber intake which suffers from vibrations at these Leader engines.

Man, you are my hero Thank you, thank you, thank you.

Thank you for your time and work you've put in to show how it's done. Words cannot express how clearer I now see everything for the upgrade I want to do on my LX 150.
I intended to buy the Malossi 190 kit but now I'm all for the Original Piaggio 200 The gasket between cylinder ans crankcase I suppose is the 0,6, right?

I don't have another option but to buy the Sito+ and I hope that it will fit, one way or another.

Will go for the winning carb as well But I believe I won't be able to use the underseat bucket after this change on the original LX150, right?

I will buy the Pollinni upgear kit. But...
Can anyone confirm that this is the secondary gear on ET4 125 ? Item Nr 2 on the drawing...
http://www.easyparts.nl/showdrawing/914/75462/-/0-968-1-m425-m6253-m1674-s914-d75462/Rear_wheel_shaft.html


I already have a J-Costa Variator to replace the factory one.

I have the entire winter to do this... so wish me luck.

Dynogrego. I am using the genuine PWK 28mm on my 190 kitted/SOHO cammed LX. I made of aluminum a 30mm extension tube from the intake boot. I then used fuel grade hose to connect from extension tube to carburetor. This puts the float bowl in its original location, the recess over the crankcase. I also use a Dial-A-Jet, similar to Mikunis' Power Jet, but with an adjustable air orifice to atomise the added fuel. Works well with the exception of a slight stumble from a stop if the slide is opened slowly. I have to open it all the way from a stop. I will try the yellow springs for the clutch as I have them on the shelf. It may help the stumble.

pixel, I made of 1/4" copper tubing a 90 degree noodle for the cable. Still I cut out a hole in the underseat bucket over the carb and the used fiberglass to form a recess for the carb. I have yet to arrange a vintage style choke cable pull and therefore must remove the bucket for cold starting. For this reason I have removed the latching mechanism for the seat out of frustration with closing my seat and then having to shut the bike off to get the key for the seat and close the choke.

Finally, I use the standard airbox with the restricting "snorkle" removed, and finally,finally, I have used a long section of rubber cooling hose to make a "Hartford Loop" from the crankcase vent on the cylinder head to the airbox in order to cure the problem of oil pooling in the airbox.

@dynogrego, You may be interested in this project of mine, Yet another exhaust mod. LX190
You might have the knowledge to get better results than I did.

1.gasket 0,6 is the choise of the most situations.

2.With this carb,you can use your basket and thats the first reason i don't use intake manifold extensions but i fit the carb direct on the rubber intake.
I just used a heat gun to modify the cap of the underseat basket to make some room for the throttle cable but i was in a harry and the result is ugly but it works.It's not difficult to make a good work but it needs some time.Sorry,no ugly photos.
But remember,my bike is a small zip 50,maybe vespa doesn't need any modification to the cap of the basket.

3.you need 9(counter shaft) and 2(wheel axle) from the 125cc model.