Modern Vespa

Damn outta always the stupid things you don't expect that cost money and frustration. Hopefully no additional money so far. Looks good!

Hopefully well see today.

Put my EGT probe in last night, since I had the exhaust pipe off the cylinder. Followed installation from an ultralite article, for installing a clamp style probe. Drilled an undersized hole for placement, smaller then the probe tip.
Then size of the probe tip, to get tip angle correct.
Then the next size up to get the angle correct, with the small hole you could adjust angle and no worry about the hole being to big.
Then the next size up to verify angle.
Then the final size which was the same diameter as the shoulder of the probe tip.

With the size on size friction fit, I could tighten down the clamp slowly, move the tip around to get the correct angle and keep tightening. Eventually it was tight and I had the probe centered, the shoulder got pulled into the hole. No air leaks at all.
I have an old Westach gauge to go with it. Need to drill the holes in the glove box and will take her out and see what happens.

I was just looking at a dyno sheet for a Pinasco 225 with reeds on Facebook. Guy says he did no cylinder port work just normal cleanup. He put v force 4 reeds in for the intake. Different pipe but still, makes me wonder if I'm leaving a lot on the table not going to a reed. Maybe their dyno is really optimistic? That's a 20 - 30% gain at 6500 rpm over mine. Might have to split my cases and clean up the rotary area and see about opening it up a bit. Don't really want to move peak torque as its about correct for cruising.

https://www.facebook.com/195581880638988/posts/1334752656721899/

Bear in mind that Pinasco does a number of 225 kits......Super Sport, 9TX, 960VTR. The Super Sport that you and I have is single port to the crankcase (like a stock P2 cylinder). The other two are more like a Malossi 210 with three ports to the crankcase

Good point I wonder which one their using, I'll have to ask.

Did you do any work to yours beyond matching the boost port? That's all I've done to mine, didnt really show any gain in the GSF dyno numbers either midrange or top end. I'm only really interested in the midrange 5800 - 6000 rpm range.

Thinking about opening up the cases, over the up coming winter and cleaning up the intake port. Maybe cutting in case ports to have for future use, something cheap to do while tinkering.

Stella seems to have survived her heart attach. I moved the needle back down to position three, to richen her up a bit, while running her in again for a few miles. The engine temperature is staying in the 235*F range at 60 mph. Egt is around 1050*F at 60mph also. I think that where she'll stay for the winter, safe place to be. The weather here is going to cool off after this weekend.

Going to go get the full size bike out for a ride now.

I did open the inlet on mine (~185 degrees of duration) and matched to the carb box, and I just tidied up the boost port to get a good match with the case. Nothing exciting for this one, but that was never the plan. Life as a 225 started with a BGM Faster Flow 24/24e, but I've since tried a PHBH, and I settled for a 26/26e, DIY modified just like a BGM FF. For distance riding with a pillion, I wanted the simplicity and convenience of the SI carb with autolube.

I'm itching to rebuild this one as a Malossi Sport 221, but cannot justify it while it is serving me so well. I can only put that solidity and reliability down to simplicity, and I can't help thinking that you are overcomplicating things with that Mikuni carb

Thanks, for the information, might split my cases over the winter and measure what I have exactly. I do like to tinker, and that is why I bought this scooter. I agree the Mikuni maybe a bit more complicated then needed, I enjoy tinkering and a good challenge.

I've had the main jet out for the most part since I started. I only put one back in a few times just to see what would happen. I have or have had what I would call a place holder jet in there. The needle jet on a TMX 30 is held in place by the main jet, so I took a 3.0 mm drill bit to a 260 (4/042) large hex main jet I had, the hole was smaller than a 1.6 mm bit. That's bigger than the inlet hole on a N-9 needle jet, the main was no longer the bottle neck. I didn't get very far before I pulled over into a park and dropped the 5EL68 needle to position 1 not enough. I put in a N-4 needle jet, from the N-6, I had already moved down to before pulling the main jet, not enough. Removed the 5EL68 needle and replaced it with what looked like the best choice to me out of what I had. That was a 5FL7, in clip position 3, I couldn't get to 1/2 throttle, in position 2, I got to 5/8 throttle, in clip position 1.5, still couldn't get to 3/4 throttle, I ended in position 1 but I can now get to 3/4 or a bit more. Now that the weather is cooling off, I'm going to see what I can find for a bit longer needle. I would like to not be out of adjustment, but it works for now.

I tried clip positions 1 and 2 today with the EGT installed, leaning her out a bit from position 3. Its interesting to see the EGT react so quickly and the CHT not move.

Notes on a 5El68 Jet Needle, it's close to a 5FP17, which you can find on the Mikuni 5 series needle chart. Measurements I got when I checked mine.

All dimensions in millimeters for a 5EL68 jet needle.

A=61.67
B=26.12
D1= 2.51
D2= 2.51
D3= 2.40
D4= 2.09
D5= 1.54
D6= 0.96


I want to get a few other needles that are close such as a 5FL11 and 5EJ11, both have been discontinued found a 5EJ11 on Ebay. There are also a few 6 series jet needles I would like to try 6F5, 6F4 and 6F8. The 6 series are a bit longer which should be fine as long as the tip isn't to big to lean out wide open.

Also bought a throttle slide with a smaller cutout, want to see what affect it has in the 1/8 - 1/4 throttle range, would like to richen it up a bit. The leaner I go with my needle and jet the leaner it seems to get. The pilot jet is correct according to what I can find, it's at about 1 - 1.25 turns. Once I get a richer slide may try going down another size and try getting closer to 1. It' an air screw on a TMX 30 so your adding air to the mixture not fuel.

Now that I've put a few miles on and have a good idea what RPM I'm going to be using while riding 5000 - 6000 or tighter yet 5500 - 6000. I have been reviewing box exhaust reviews. I currently have a Sip Road XL doesn't get the best reviews in some places, but doesn't look to be bad in my desired rpm range. In the Scooterlab test they show a stock P200 and a Malossi 210 Sport. Should I be looking at the stock P200 graphs? I'm just trying to figure out which one has the best torque in the 5800 rpm area.

https://scooterlab.uk/vespa-big-box-exhaust-shootout-feature-2/

https://www.scootering.com/the-vespa-big-box-exhaust-test/

my road xl once on my 15hp+ engine really excels in that range and higher. It hits a power band around 4500 and throws you back in your seat as it starts to take off. So its good around 5500-6500 rpm. I see it never fully gets great reviews, but I see it as a compromise of kinda good at the high end hp and still decent at the low end torque. I've been seeing a lot of other newer boxes that look better but it works well enough for me and isn't super obnoxious loud, so it stays until its dead.

Many needles will overlap. Try one and decide what you don't like about it. Then choose one that fits where you want to go next.

If you keep the pilot jet small at 1 to 1.25 turns, slide mid range and main jet at your 260, it will be easier to pick a needle and atomiser. And for these just focus on 1/3 throttle. When this is running good, check 5/8 and if this is also good the needle can stay for the next stage.

A well set up carb has the clip on 3 and the airscrew at near 2 turns, once all done. Sounds so easy.

Edit: definitely cheaper to tune an engine to an exhaust. Find one you like and adjust the cylinder to it.

I can only speak to the 150 version of it, butI have a couple SIP RoadXL's and they've been solid performers for me. I can't compare them to the alternatives (BGM Big Boxes, Polini, or Pipe Design), though. It's a little bit wider power band down low compared to the PM Tuning expansion that's on the bike now, and definitely more punch than a Road 2.0. It's a solid performer once you get it set up. I have one on my SprintV motor, too, and while it's not nearly the screamer that my LML motor is, it's still a really solid performer and I've been very happy with it as part of a more "touring" build.

I will note that something broke loose inside of it as I was bashing it on the ground while trying to keep up with CM while he was in town, so maybe the interior welds aren't all they might be, which others have confirmed when they opened their XL's up after shaking them and hearing things rattle.

I'm really close with the current setup, Its definitely useable. If I don't find a needle I like better, 5FL7 will go back in. If I get some decent weather, I would like to try a few different main jets, just to see what I get. I was thinking of putting in a big jet and working my way down to see, what the jet does to the 1/4 - 3/4, throttle range.

I ordered a smaller throttle valve cut out. I've always had a lean spot I could work around, hoping I can get a more robust 0 - 1/4 throttle setup. There's a lean spot at about 1/8 throttle. Part of my work around has been to adjust the mixture screw a little rich on purpose. I figure a throttle valve is easy to replace, and it will be a good learning experience that's not theoretical.

Looking at box's would it be a bad idea to lower the 60 mph or 97 kph, rpm to 5000 some how? Would it make the gearing to tall to move and create other issues? Would the longer gears cause issue pulling a hill even though I should have more power at the new 60 mph rpm?

The reason I ask, according to the above dyno charts, I can put on a a few different box exhausts, such as a BGM touring or TSR vortex, that at a lower rpm, gain 11%+ in hp and torque over what I'm currently running at 5800 rpm. I see people putting longer gears in to reduce rpm and get a faster speed. Not really looking for a faster speed it would be moving my power and torque to a lower rpm. This would be a 14% reduction in rpm.

Pulled intake to see what I have, looks like I have a little work to do.

Area of 30mm carburetor = 706mm

Area of rectangle on bottom of intake block = 24mm x 33mm = 792mm

Minimum size needed to get 706mm = 24 x 29.5 = 708 mm

Optimistic area of gasket hole 22.76 x 30.55 = 695.32



Anybody know the area of the hole in the factory gasket?

Working on pictures.


Need to fit the intake to the block, any reason I can't take a little off the front over the drilled hole in the intake surface above the rotary valve?





Need to fit the MRP block to the gasket. Will take a little off the back.

Christopher - my $.02
I find that the MRP block is not machined so that the edge closest to the flywheel has very little room for error.
You can widen the case there - but be careful not to leave yourself with too little surface for anything to seal to... See pics below.

As for the large area at the front - looks like you have plenty of room to work with. There is a case stud you need to be aware of - but appears you should be able to take the inlet forward safety to me.

The other area you have to be aware of is the seal between inlet opening and the rear carb stud. Looks like there is no more room to move there to my eye. You dont want to loose that seal - because it can then potentially suck air through the studs hole.

Looks good!


This area between the small green lines - gotta be careful not to remove too much as there isn't as much clamping pressure there.

That little strip between rear carb stud and inlet I would leave alone.

I see what your talking about on the flywheel side, not much there. I'll set the block back on and see if it has some play to just slide it to towards the tire. I'll steer clear of the stud also. If someone did make a mistake by the stud, do you think a silicone gasket maker, could be used around the screw when inserting it into the block?

Going to get a width measurement of the rotary pad opening today. I can see why people put in reed valves and spend so much time optimizing the width of the rotary valve opening. Just looking at theoretical bottle necks, the inlet looks like one using a 30 mm carburetor. It would be interesting to see a before and after dyno run, of an optimized rotary valve inlet. Wish it was a bit warmer here to try it. My Calculated area size of the inlet hole is optimistic at best. Taking out the area for the corners, since I made it a square, it doesn't quite have the same area as a 30 mm carburetor. Even at that its a funnel down to the rotary valve opening. This means the actual opening is smaller yet.

Biggest carb for a rotary inlet has always been 30mm. Even fully opened out at 220 degrees, a 30mm carb is enough. Like was said on the CM1 thread; the rotary technology is excellent, just way too small. Converting to reed is the only way to make it bigger.

I think your Pinasco would be best suited to a rotary inlet at full width and opened out to 185 degrees. 26/26 carb and VRX vortex. Can still run autolube then. I know this works well because this is the set up from my 200 tourer.
Might be worth doing when you next change the cruciform.

I've been contemplating a lot lately with covid and staying home more, to much time on my hands, that's when I get myself in trouble. Splitting the cases, over the winter, maybe the next few weeks, is one thing I've been contemplating. Having never split a set of cases is one reason I'm a little nervous or hesitant.

If I can open up the intake tract width and keep my power and torque in the 5000 - 6000 rpm range, I don't mind splitting the cases. Don't see why that would affect power rpm range. Hopefully it will give me more just not sure why it would shift it around.

If I can extend the intake to 185° and keep my power and torque in the 5000 - 6000 rpm range I don't mind splitting the cases, and trimming the pad and crankshaft where needed. I have an angle grinder which I have seen people use to trim the crankshaft.

I was also thinking of cutting in case ports while split and opening them up in the cylinder. Not sure if there is much of a need or advantage with the size of the transfer ports that are in there now.

I think these can all be done without much chance of me messing something up and just needing new case gaskets. Something to cut my teeth on.

I can order a set of gaskets from Scooter Mercato so that's not an issue. Are the case gaskets for the 5 port LML motor the same? I have two sets here that I never used as I never split my lmL cases yet.

Not 100% sure what I will need to split the cases, I have the specialty tools to get the clutch and flywheel off so that's not an issue.


Ok to much time on my hands, time go do something.

Need vespa gaskets. If taking it apart for the inlet, then doing some cylinder work is easy power.

Do you have any more pictures of this plug ???

Which plug?

page three.....

Wasn't sure if you're talking up the plug for the power jet or the spark plug?

The spark plug pictures are from last year, not sure what I might have without searching through pictures. Anything in particular your looking for?

The power jet plug is just two pieces of hose with a screw in the ends.

Bringing this back up, will see what it looks like with reeds, same everything else. We can see before and after on GSF. Don't ride scooter hard, mainly just for around town and occasional ride for ice cream. If I kill the Pinasco piston I'll get a Malossi Sport I guess. Will switch carburetor back to all rich jetting and work my way down again.


Where should I drill for a fuel pump vacuum hose? Thinking I should install nipple now. I'm thinking I may stick in a larger tank which would put fuel outlet below carburetor.

You have 2-3 options:

- In the crankcase, just below the rotary pad (towards the rear shock)

- in the intake manifold

- in the carb at the back (on the manifold side)

I've done 1 and 3, both work pretty well after testing, re-testing

But I've seen a lot of folks do 2 too.

With 2 and 3 you can keep the cases untouched…

But honestly, unless you have a 34mm or upwards carb or a tmx (because of the float bowl… I don't think a pump is needed. Just my 0.2c and past experience

He needs the pump to lift the fuel up from an expanded tank, 108, but I agree that most people don't need a pump, even under abnormal circumstances.

I have run my pump on the carb, but found the performance could be iffy. I drilled my reed block and installed a nipple there when I migrated the motor to the GL and it's an absolute champ. Left the cases unmolested (for once), but I did it there to avoid splitting the cases, not that it mattered since that was when I dropped the washer into the crankcase and got to split them anyways...

Yeah intake would be least hassle

Going to need to put one hose on intake for vacuum fuel Petcock operation and one for pump that oscillatees.

Chandler didn't you use a mechanical pump from a go kart place with a built in regulation?

Yup. This one Dellorto. Been using it for a few years now and it's been flawless.

Thanks, I want to start tuning with pump hooked up in case it makes a difference. Technically it shouldn't as long as fuel bowl is always full but!!!

No harm having a pump, whether needed or not. If you have a reed block, this is the best place to drill into. On the engine side of the reed gives the best results.

Finally had a bit of ambition and checked for air leaks, ended up with 0.5 PSI in 12 minutes. Acceptable from what I can find, I know where a leak is but don't want to pull head. I put sealer on base gasket and don't want to brake that seal. That leak could be a cylinder stud thread leaking.

Used simple green and a foaming nozzle to spray motor down. Bench smells much better.


MRP reed intake installed, with RD350 Vforce 4 reeds. Intake opened up a bit also, didn't touch crankshaft at this point.

Going to put TMX30 carburetor back to original jetting and needle, that setup was richer everywhere. Easy enough to lean things out. Intake opening is now larger than carburetor opening so might move a bit more air.

Not going to change anything else want to compare reed vs rotary intake power band spread using GSF dyno.


Small slow bubbles

MRP reed intake, had a small leak, screws were a little loose.

It runs, with reeds, jetting in video is Mikuni TMX30 carburetor setup with 27.5 idle jet, factory EL68 needle raised one above middle ( moving needle up towards top for a richer setup), factory n-9 needle jet, 4.0 slide and main jet drilled out to some huge size with a drill bit. Main jet holds needle jet in place so I needed a holder and didn't have a main above above 260 to create really rich for initial tuning of bottom end jetting. Will have to get some 300-350 main jets.

Second run 1st wasn't anymore eventful. Was surprised it started so easily.

https://youtube.com/shorts/bA5n4Dq7FJU?feature=share

https://youtube.com/shorts/hyFp4xkkPT4?feature=share

NOTES

Cruising at 1/4 - 1/3 throttle

Pilot Jet 30

Needle 5EL68 @ top notch as lean as possible.

No real main jet

Stutter 1/3 - 1/2 throttle

Cruising @ 55mph

Spark Plug Temperature 255°F

Exhaust Temperature - 1300°F[/b]

if you know where a leak is, you'd best fix it. small leaks grow. easier now than once your motor is toast.

Agree with John.
Keep in mind - the head/cylinder/combustion area is experiencing high pressure compared to to the cases.
Any leak at the head would be one I would want to get rid of.
Porting looks good.
Interested to see your findings with GSF dyno.
Cool one.

I've been working on jet needles and needle jet setup for my TMX30, I'm doing all of these test with a main drilled out to some obscene size and it is just holding needle jet in place. When I say works up to half throttle I can cruise there at 60-65 mph for a mile or more, not some 1 second fluke. I am watching my EGT, CHT and AFR. AFR is most sensitive to changes, EGT next then CHT. CHT is slow to react compared to other two indicators. I have 0.5mm shims for fine tuning needle placement.

Replaced factory N-9 needle jet with a larger 0-6. N-9 was just to lean everywhere below 1/4 throttle. 0-6 took care of my lean off idle and 1/4 throttle issue with jet needles I have.

5EL68 factory needle taper is to steep, didn't work on rotary or reed couldn't even get to 1/4 throttle, previous setup when I bought it was using a 260 main, but main was restriction not needle setup.

5FL7 promising, was little rich on leanest notch, could get to 1/2 throttle or maybe a bit more. Was still a bit rich on leanest notch, pulled pod filter for fun of it and it leaned out a bit from idle to 1/2 throttle. It wasn't stumbling or stuttering rich any longer. Great another tuning issue.

5DJ8 looks like same needle for most part as 5FL7, didn't try it yet. Tip is 0.07mm larger diameter than 5FL7. Might get a little more than 1/2 throttle.

5EJ11 works also needs to be tried more between notches 1, 1.5 and 2. With pod filter removed 2.5 would no longer work and was lean. Had to put pod back on and ride home. I saw 16.6 AFR without pod and EGT was climbing quickly. Put pod back on dropped back down to low 13's. This was all at less then 50% throttle closer to 1/4.

Need to get a dumbo air tube to frame setup before I spend to much time trying to tune with a pod filter setup installed apparently, before any more fine tuning.