Modern Vespa

Hello everyone! This is my first post so I guess I should introduce my scoot a little.

I have a 2009 Genuine Stella which I bought with 1700 miles about a year ago. Since then it's gotten to almost 4600 miles, and it's acquired a SIP Road 2.0 pipe with the long tips, Bald John jetting, and de-blued stock filter.

In the past month or so I've run into some extra funds, and I did my first major round of upgrades, including a VMC Super G cast 177 kit, GGR hot reed, Mazzucchelli economy crank, new Michelin S1 tires, new Malossi Sport brake pads up front and SIP performance brake shoes in back, new FA Italia rear drum, and some other various dress-up things.

I've got everything installed except the new reed and crank. Since the infamous stock Stella crank has lasted up until now with no issues I got a bit impatient and threw the kit together without doing the crank replacement just yet. I was unable to get the philips screw holding the reed block on without boogering it up because of the loctite used from the factory

The stock LML filter, even in its de-blued state, seems to be too restrictive for the SI 20/20 carb combined with this kit. For now I've got a UNI pod filter on the way, to be clamped onto the airbox in place of the rubber bellows. Also, I couldn't get the PBT less than ~1.3mm even with the smallest base gasket. The specs call for a squish of 1mm +-0.1. I forgot to measure the head's squish band but I think it's around 0.3mm. So far I don't have any knocking so I'm not too worried, but it is something I want to remedy in the future.

Since I need to drop the engine either way to get these new reeds in, I was wondering if I should try tackling the crank replacement myself too. I don't have a crank puller or anything yet, and I'm a little worried about biting off more than I can chew with a project like that. Up until now I've done all the wrenching and part installations myself, but I've never done anything that requires case splitting or engine removal. What do y'all think?

Thanks in advance everyone!

Good looking scoot and sounds like you made some nice upgrades. If it is riding well… I d probably leave well enough alone until riding season is over. Then, I'm sure you could split the cases and pull in a crank. We are happy to help and/or point you to vids and resources to get you sorted.

For now I'd get cht gauge on the VMC and monitor your heat.

Man, I bet that's a fun little ride with the 177!

Welcome!

I agree nice looking Stella, looks like you've been having fun so far. What did you use for thinnest base gasket? You can buy thinner material and make your own, that's what I've done in the past to adjust squish. Not sure, where you purchased crankshaft from, but if you can return it for a 60mm crankshaft you would be able to adjust squish to your nominal settings. Not to mention a little extra power.

I've got a trailtech CHT gauge on the way right now. FedEx stuck it in my mailbox and USPS took it while delivering my mail, so I'm currently in the process of finding it again.

Everything is riding "fine" so far, but there is an alarming amount of vibration coming from the engine during most of the powerband. There is one spot on the electric start gear flywheel that keeps striping the side of the cylinder as well, even though I shaved it down pretty far. I can't tell if it's because of some tolerance weirdness with the flywheel, or bad truing. So far I've been torquing the flywheel down to 45 ft-lb with the screwdriver between the fins and kickstart lever method.

I know part of the problem with the stock Stella/LML crank is the extremely bad truing (to the point where you can measure the runout with a ruler). https://youtu.be/3246VUw2Sqs?t=253

Since I'm taking this to the Smoky Mountain Smallbore rally in June, I would hate for it to crap out on the Dragon or something like that. The thinnest one that came with the kit is 0.1mm. I got the crank from scootermercato.

That is a very nice looking Stella.

As you may know, mista FreakMoPed has made some videos about the VMC 177 Super G. Among other things, he reports that the squish band in the head starts flush with the bottom of the head, such that it adds 0 to squish. In that case, your 1.3mm isn't so bad.

Also, not sure why you say you need to drop the engine to install those after-market composite reeds. Personally, I would just stick with the stock reeds but, if you're dead set on having reeds that need regular replacement and have nothing more than butt-dyno results to back them up, just remove the reed block (3 screws) and have at it.

Happened to notice today that Scooter Mercato is offering loaner tools for that crankshaft replacement. If you buy your parts from them and then return the tools within 30 days, the charge is only $20. Wish I had known about that when I did mine.

don't quote me as a source but i thought the bad cranks were earlier in time than 2009. greasy might know, rob hodge would know but won't read this, perhaps others know....

never mind, I was wrong:

stella crank question ; failure issues

I believe that is for the VMC Stelvio head, or whichever has the horizontal fins. I could visibly see a squish band on mine, or what I think is a squish band, comparing to heads without one. The philips screw up near the oil pump gear on mine was heavily red-loctited in place, I've boogered it up a lot trying to get my impact screwdriver onto it, to no avail. I even blowtorched that area a bit to try and break down the loctite but I still can't do much without a proper angle on the screw. Since the frame is in the way, I'm left with the option of dropping the engine to give me a solid top-down angle on the reed block.

I've already got the GGR reed kit on my desk so why stop now?


Squish band or no?

Good on you, sir. Fortune favors the bold!

This fella groks vintage.

Welp, as I threw another quart of oil in, I noticed the top of the exhaust is very oily, and after my 2nd ride I saw a lot of oil seeping around the left side of the floorboard, at the seam between that and the center piece. I also noticed small bubbles inside the sightglass. Not sure if I messed the oil line's connection up when I put the tank back in after installing the SIP tap, or the sightglass is cracked, but I'll take the tank back out this week and find out.

Ive had a pretty full refresh kit (gaskets, o rings, internal seals etc) sitting in my scootermercato cart for a week now, plus the loaner kit for replacing the crankshaft. I threw in an oil line and new sightglass too. Also picking up a fly racing engine stand.

How long do y'all think a crank replacement will take for someone's first time splitting a case?


Another update: finally got my CHT gauge, maxed out at 330F on a 20 minute ride at around 40-50mph. Haven't gotten a chance to really romp on it yet though

If you want to a day. I just did mine for the first time, watching Scooterwests videos on YouTube, while taking mine apart took me a few hours to have my motor sitting on a large bench in pieces. Watch SIP videos on motor rebuild, good videos with specifications. I was watching videos while putting mine together. I used motor sealer on some gaskets and waiting for it to dry, have been busy this week so hopefully a pressure test tonight or Friday.

Be prepared to make a second order for something small like shim on gear set. I you don't own two sets of feeler gauges with a 0.10 mm shim get them before you take motor apart to save time.

You don't need to pull your motor, you can change out a crankshaft in frame if you want to. I would still look at getting that 60mm crankshaft if you haven't yet. Same job no extra work and a little more power, you know you want more power.

Also spend time watching those videos before hand to become familiar with what you're doing and get an idea of tools you should have sitting on your bench. Do you have an inch pound torque wrench? Something smaller in a 1/4 drive. Also a good set of 1/4" drive sockets and extensions. This thing is aluminum no need to strip out threads over tightening things with a 3/8 drive ratchet. Also sockets for that large bolt going through motor mount. It's a larger size than my metric sets did not include had to buy two specifically for this job.

I thought the sexy CNC head was standard on the Super G, and was the main reason people bought that kit. I see now it is a $25 upcharge when you buy the kit.

I can't tell from the photos whether the standard head has some squish built into it.

I wonder what it costs to buy the CNC head separately.

I got the Mazzucchelli 57mm economy crank from scootermercato. Maybe I'll go 60mm if I end up doing another big round of upgrades but for now this should do. I'm fairly happy with its current power level, and I can always unlock some more by shaving the head and case matching, and maybe upgrading to a SIP road 3. I'm more concerned about reliability right now since I'm getting tired of my stella not being potty trained and leaking all over my garage I've got a 1/2 drive torque wrench already. It measures in ft-lb and goes down to about 10. However, for most stuff at that spec and below I'm pretty comfortable doing it by feel.

I've been using my impact rated sockets (up to 24mm) and an extended ratchet for large bolts so far, and I have a wrench set that also goes up that high. Getting it from both sides shouldn't be an issue.


Also, it turns out the scootermercato loaner kit is only available if you also buy an engine rebuild kit from them, so while I have an engine stand on the way, I might have to wing it for pulling the new crank into the bearing.
I saw a video by Vespa Motorsport's Robot on a P200 rebuild, and he simply used the clutch nut and an impact to pull the new crank in. Seemed pretty smart to me, has anyone else tried this?
https://youtu.be/yaH9NhEZ0Bk?t=4219

I did this except I used a ratchet instead of an impact because I wanted to be able to feel if something was getting hung up. Worked well for me.

Small update:

Was able to make it to this year's Smoky Mountain Smallbore Rally with both of my scoots! Went with a friend who brought his Elite 150 and a Vino 50 with a 70cc polini kit (which unfortunately ate a circlip on the way to the rally). Funnily enough the Stella was the most reliable scooter for the whole trip! Gave me no problems at all. Got to hit the tail a little too!




I have elected to further put off installing the new crank until my helix has all its maintenance finished, and when my garage isn't 90+F all day haha. Since it still has the LML crank as mentioned before, I have just been taking it easy to not test my luck too much.

One of the problems I have dealt with ever since I installed the VMC kit, however, is the stock e-start flywheel contacting the cylinder. I had to remove the cylinder and grind it down at least 3 or 4 times before buttoning everything up, and I still encountered a little bit of noise after the fact but I got so tired of working on it that I just let it slide. A few days ago I had the flywheel off again to try and get rid of it once and for all, and while it worked at first, it has slowly started to come back. Is this a sign that the crank pin might be finally giving out?

I eventually plan to just get the SIP lightweight flywheel and get rid of the electric start system. Honestly in the meantime I might cut the ring off the stock flywheel too.