Modern Vespa

I ground down the weld on the fork stop. It looks like it should do the trick.

And with the fork slipped back in place...

I got around to porting and flowing the inside of the intake manifold. It's a much straighter shot, and the manifold flow now lines up with the intake on the case.

And what it looks like next to the engine case.

And when I went to turn on the air compressor this morning, there was a huge moth hanging out on the shop door. It had about a 5" wingspan!

I must set up that spool gun! So many uses for it.

I guess you don't want to open the case to match up the manifold from the inside, would be nice as you've done a good job getting that right. Is the manifold not a PK one, is that why it's so much smaller?

Yeah, the aluminum spool gun is super handy. It's definitely not the best tool to do any small intricate welding though. That's where a TIG is superior. A spool gun also throws LOTS of sparks and dingle berrys everywhere, so the material that you're welding on will have weld splatter stuck to it. I don't own a TIG welder yet. The ones I'm looking at are around $3500, so I'm really in no hurry to buy one!

I actually did open up the intake a smidge on the case today. It only needed about 3/16" removed in just one area to get the flow all lined up. I squished in a piece of closed cell foam in the intake track, stuck a vacuum hose next to the opening, and spent less than a minute flowing it with a die grinder. I was quite hesitant about doing it that way, but there was zero intrusion of any sort of aluminum that got past the foam.

The intake (24mm Polini) is definitely a 3 bolt PK intake. No idea why the I.D. has such a small opening. I'm sure the SIP description of it went something like this..."ultimate tuning for max racing speed potential. Suitable for carbs from 40mil to stock".

Here's a pic of the area on the case that I flowed...

I did clean up the welds some on the manifold. I had no desire to sand out each and every pit in the welds, so this is as good as it's going to get.

I also rattle can painted the fork. I didn't want to disconnect the brake hydro line, so the fork got painted in the most awkward position possible. I'm not going to do any fancy paint job on this scooter. If I ever found a different (nicer) PK frame, then I would probably do a nice paint job and powdercoat the fork. So for now $5 worth of paint will suffice.

FYI, under the brown paper and blue welding jacket is the PK...

some good work going on there and the moth is a beaut!

Ha! Sometimes you'll go to great lengths to avoid those terrible jobs you hate - ie bleeding the brakes! I usually end up on the verge of tears of frustration when I do it. I see SIP has a fancy bleeder screw (Stahlbus) that they say makes it really easy. But didn't have the version I needed. I found Goodrich do one a lot cheaper, it's called Speed Bleeder... has a ball bearing on a spring that stops air getting back in. Actually a few people seem to make it now I look a bit harder.


I ended up in a similar position last week, though it was because (like you) I replaced the axle, and didn't think to check if it was pushed in far enough before fitting.


Still experimenting with my Full Flow engine design. Very economical so far.

interesting thing the speed bleeder!

what size is the appropriate one for a standard vespa front caliper?

It measures 9.8mm across the threads, so must be an M10. Threads appear to be 1.0. But it's different to the one above, there's an indent on the end, which locates a ball bearing to seal instead of the usual taper. You may be safer with the one from SIP.

Sorry for the diversion WDC, on with the entertainment!

I installed speed bleeders at all four corners in my Jeep CJ about 15 years ago. Funny thing is I never got around to actually utilizing them. I have a brake bleeder pressure pot tool that holds a little more than a gallon of brake fluid. You pressurize the pot to about 30psi, then hook up the pressure pot's hose up to the master cylinder (with a custom adapter). Twist the pot's valve open, as well as the bleeder screws, and fluid will shoot out of all four calipers at the same time. It makes it so you can completely flush an entire brake system in less than a minute!

...and that's why I never got around to using the speed bleeders.

Ugh...what a horrible position to be in! I had the same problem with the axle that i pressed into my pink PK200 project. The replacement shims, spacers, clips, and bearings didn't quite like up the same as the old ones, so i had to press the axle back and forth quite a few times to get it just right. Luckily the fork was out of the scooter though!. I probably had the fork in and out of the press about 15 times to get it exactly where i wanted it...not to much end play, yet at the same time, i didn't want to crush the rubber O ring that's seated against the swingarm pivot.

That sounds great! An attachment to the Piaggio m/c may not be that hard to make. Hmmm.
Yes it was about that time that I was happy I went the cheaper option and bought a press that I can actually lift around the garage...

I placed an order for a tach and CHT gauge from TrailTech about 2 weeks ago. Apparently the readout took so long was because they were out of stock?...I'm a bit skeptical, but whatever. Since they're located only about 45 minutes away, when they finally did ship the parts, it arrived the very next day via UPS.

I wanted to install a CHT in the cylinder head before I buttoned up the top end. I didn't want to install one under the spark plug, and there wasn't enough clearance to mount it under a cylinder head nut either. To I took a chance and ordered their sensor that has a 8mm wide fin. It would just BARELY fit between the cooling fins at the top of the head. I took a file and smoothed our the surface a little bit so that the sensor would have good contact.

I drilled and tapped a 4mm hole in the cylinder head so that I could bolt the temp sensor down (had to drill a hole through the sensor too).

Once screwed down (I'll install a lock washer at final install), it fits quite nicely. The cylinder head is very thick where I drilled the hole, so it seemed like the perfect spot for the sensor....which also happens to be directly in the top center of the head. That spot should give some pretty accurate readings (in theory).

I ended up getting carried away and installed a second 4mm screw. I simply just peened the sensor tab over and drill/tapped another hole. It's probably not needed, but I did it anyhow.

I also assembled the front fork and installed it back in the scooter. Since I didn't want to disconnect the hydro brake line, i couldn't use the steering column tool for tightening down the bearings...until I cut a 1/4" notch through it. It didn't seem to affect the performance of the tool so I'm cool with it.

Nice improvising. Shouldn't affect the performance of the tool, given what I hear, that is only supposed to be finger tight anyways, so you wouldn't be flexing the tool during usage.

The bottom bearing needs to be torqued down just a little bit, then backed off "X" amount. Then the spacer washer gets slipped over the top, finally a second nut gets installed and torqed down fairly tight. Haynes specs out about 25ftlbs for the PX and about 40lbs for the P model. I have no idea why the discrepancy in the Haynes manual. Both the P and PX both use the same cups and bearings. Beedspeed shows that the torque is about 40ftlbs for both the P and PX, so i would go with that setting. So installing and torquing the steering column is exactly the same as it would be for the wheel bearings in any automotive vehicle that has front wheel bearings that have to be preloaded (non-unit bearing hubs).

I did put my arm into it to torque down the outer lock nut and i didn't see the tool flex, so i think it should be fine to have that slot cut in there.

Nice job with the sensor wire. I might want to do something similar. It's a pain around the spark plug...

nice job on the temp sensor and tool. Might have been a little nervous drilling the hole.

Yes, yes it was

Thank you Scott! On my T5 i have the sensor under the plug, and it isn't a big deal in that application because i milled vertically straight down one of the cooling fins so that the ovalish shaped sensor is kinda "keyed" into the head so it doesn't rotate when the plug is tighten up. On two other PX200 engines i have them mounted under a cylinder head nut. I would have done the same for this Parma cylinder head as well, but there was no way to install any sensor under the head nut. So after racking my brain for a few days, i used an 8mm wide sensor fin (a 7mm and 10mm wide are available as well from TT).

Last edited by whodatschrome on Sat, 02 May 2020 08:08:29 +0000; edited 1 time

Really like both of those ideas. The sensor especially!

The fork is back in place with a new OEM style Carbone shock from SIP. The YSS shock that I installed about 50 miles ago didn't make the cut. It had just WAY too stiff of a shock spring and had piss poor damping. There is also more room to fit the Carbone shock under the fender (because of the offset caused by the disc brake kit) than the YSS shock. There is also more room to physically bolt the top shock place to the upper fork shock mount bracket. The existing 35 year old shock still had damping that felt excellent, but I needed a little bit stiffer spring rating. Hopefully this new Carbone shock will give me what I'm looking for.

So nothing fancy looking at all in the front suspension, but function follows form this one time. Plus I kinda like the nonchalant grey color going on in that whole area.

Pics of the stock shock disassembled next to the YSS. The stock shock has a longer travel stroke. You can also see the difference between the two springs. The front YSS spring even has a much harder spring rate than a stock rear spring on a newer PX150!

I got around to installing the Polini intake manifold today. The intake came with longer bolts, but I decided to use studs and nuts instead.

The outside diameter of the Parma cylinder is a little bit different shaped than the stock 125 cast iron cylinder, and that creates a gap where the screw goes through the flywheel shroud and the side of the cylinder. I need about another 1000 words to describe completely, so I'll post up pics instead. Anyhow, I got a 9mm long aluminum spacer to weld to the cylinder.

What it looks like threaded into the cylinder.

Here you can see the Polini intake mounted up.

I was thinking about welding the spacer on the cylinder with my spool gun, but it would have looked like crap for a small tack weld like that...so I "phoned a friend". He has a VERY nice water cooled Miller TIG welder at his place. He spent about minute tack welding it. I was VERY pleased with his quick work! He's one of my dirtbike riding friends AND he owns a business that manufactures navigation equipment for moto rally racing (think Paris Dakar). Probably close to 95% of all professional and amateur rally racers/riders around the world use his rally computers and switches!

This is what it all looks like with the 3mm thick shroud spacer and fan shroud bolted back up. That aluminum spacer is 9mm long, so that means that the Parma cylinder is 6mm short in that area (compared to the stock 125 cylinder).

I now need to make a quick decision on which exhaust to use. I'd like to find an NOS PK Leo Vince Secsys exhaust, but I doubt I'll ever find one. I don't want to wait for a custom pipe design, so I'm thinking about and LTH? I'm not sure if I should go after their "road" or "mid range" pipe though since I have a 174 degree exhaust timing and a 25mil Dellorto. I'm reading that their "road" version is for engines with less than 180 degrees, while their "mid range" is for 180 through 190. What that tells me is that I should go after their "road" version, but one of my friends tried it out and he said that it felt a little "choked up a bit" at the higher RPMs. Then again, I'm not trying to build a "race engine", I'm after a touring engine that has some toque to it.

I can't tell you how it runs with the LTH mid range, but if you need any measurements - I'm your man! Just collecting dust at the moment.

https://www.lambretta-teile.de/Exhaust-LTH-Midrange-Curly-clear-coat-Vespa-Falc-Parmakit-Polini-Evo?fbclid=IwAR3FSzW_vFca_Ae-LWZnAdg3ilzq4QZcR43vYKfMd5fYSyhblgE8QwVVaQQ

Long time bump.

The bike has been under a tarp for quite a long time now. I've been working on other various Vespa, truck, car, Jeep, farm tractor, dirtbike projects in the meantime. I was waiting for at least a year for the LTH road to come back in stock, but they never did. So about 4 months ago I decided to buy an EGIG Superbanana Touring pipe. The whole mounting assembly (and the associated parts that came with it) were just to floppy and soggy to be reliable. There was at least 1" back and forth play on the main body of the pipe! So out with the welder and grinder...

And here are some pics of my Touring Superbanana.

My finger is pointing where I had to spot weld where EGIG's weld didn't quite make it all the way around the lowest cone.


The pipe also only comes with one set spring hangers and one spring. I welded on a second set of hangers and added a second spring.


The black colored rubber vibration isolators are too small of a diameter and too soft of a durometer. I experimented with a few different sets from McMaster Carr. The orange ones in the picture work perfectly.

The mounting bracket is about 1/8" thick. It also has overly long elongated holes. No doubt that 1/8" thick bracket will have a short work life before it cracks apart. I lucked out and had a length of 3/16"x 4x4 square tube in my shop that worked perfectly to make a heavier duty bracket. I also welded in a gusset to further strengthen it.

Also the exhaust manifold was welded slightly off into the exhaust flange...which meant that threading on a washer and nut was impossible. With some hammering and a grinder, I could get the nut to thread on, but just barely.

I also had to hack the holy heck out of my PK frame to fit the Superbanana. It may look like I cut way too much, but I removed just small bits of sheetmetal at a time, so in actuality I cut out the very bare minimum of metal from the frame. I removed the rear shock in order to measure how much suspension up travel there was, then started cutting and grinding
From there. I'm not really pleased with the amount of sheetmetal that had to be removed in order to fit the pipe, but since the PK isn't in the greatest of condition, so I can let it slide.

It's certainly frustrating to spend good money on what is a basis for a diy job, but it seems to happen over and over with scooter bits. Anyway nice job you've done there as always. I ended up cutting a slot in the mounting flange of my LTH midrange which made the job a bit easier.

I sure hope it's a good pipe anyway!

I sure hope it's a good pipe too Ginch!

For some reason I wasn't too frustrated with modifying the pipe. I think mainly because just about everything needed to be fixed or modified on it, that it just became an exercise in problem solving, rather than complaining. OK, I guess I got one more complaint...the EGIG pipe comes as bare uncoated steel. Which means that I must be painted with something. It would have been nice to have it precoated from the factory.

Now for the bonus of the pipe!
-there's plenty of clearance for both the rear shock and tire.
-there's plenty of clearance for a 3.5x10 SIP tubeless tire.