Modern Vespa

Uhhhh…piston ring stops…

Is that a Vespa thing?

That's what happened. I was aware of piston ring orientation, but have never heard of stops. I haven't come across it in my reading…until looking for new rings.

Not new a 2 stroke motor has ring stops to keep orientation from moving. You don't want ring ends rotating into a port.

Riiiiight…Rings on a 4 stroke just have to be offset…they will probably move around, but having the ring gaps line up is so cosmically unlikely and no ports to snag the ends…

I get it. I didn't even know the stops were there, until I snapped a ring. I spent some time fiddling with a stock piston and it became really clear what happened.

It makes me feel slightly better to know that I'm not impossibly gorilla handed…just didn't know what I didn't know…

Still gotta find new rings Polini 177 Sumpin' sumpin'….

I am considering starting from scratch. I would be pissed to get new rings, put it all together and find through the pressure test that I had to replace the main seals, whatever. Maybe it makes more sense to just pull it apart and go through everything. It's the 2 steps forward, 1 step back that is really frustrating.

I will walk away for awhile and just let the idea settle.

Caveat: I've never had a Stella...

Judging by your gasket, you're getting oil to the engine. I'd rule that out. It's a pretty solid system, under little mechanical stress.

You can pressure test it without the rings.

If you're talking about the crankshaft seal, that should the last of your air-leak searches. There are several, more usual suspects, that won't involve a deep dive to find.

Thank you, That's a helpful video. Usual suspects are the stuff you bolt on. I will try the pressure test tomorrow and go from there. I will call Scooter Mercato on Monday and try to find some new rings.

Swiss1939 nailed it. I've wanted to throw mine in the river at least 23 times already. The one step forward two steps back is extremely frustrating. Keep at it though. It's worth it when you get it running.

I worked on mine for over a year and noticed last week that the frame is twisted. It sucks. But it's not noticeable when I ride, even at 70mph which is friggin frightening honestly, so I'm just gonna ride it till I save up cash and find a straight roundtail.

If you don't notice it 70, it doesn't seem like there's a lot to notice. I have read a lot of build threads and it's a similar theme. I know it gets easier.

Thank you for the encouragement.

Not doing much today other than rebuilding the 200 carb.

I'm not going to do the pressure test on the Stella until I can put rings in it too. Trying to avoid the extra work of installing the studs, head and p and c, then doing it all over again.

Going to pressure test the 200 engine and see how that does. I know it's been resealed under 1000 miles ago.

I also have this LML bottom end on my workbench. It's used but seems to be in good condition. Im going to replace the seals, bearings, crank and cross while I'm waiting for parts, etc. I also have a stock LML top end and clutch.

I should end up with one decent engine and hopefully 3. They will all find a home eventually

Got the 200 carb rebuilt.

And welded up the pieces I cut out for my engine stand. Ugly, but it works.

I have the spare engine apart and plan to replace the LML crank and bearings. I am feeling like the engine that's on the Stella now may be getting a bit long in the tooth to be running a kit and upgear with the stock LML parts. It's got 4,000 miles on the clock.

I mentioned the rattle I heard in the engine and am wondering whether the engine seize might have been the con rod, at least in part. Second gear also misses when I shift sometimes and after riding it for awhile, I'm pretty sure it's not my shifting.

Either way, I think it would be easier to just bite the bullet now rather than replacing stuff bit by bit. I liked the Polini kit, though I don't have anything to compare it with for feel, but I could always change the top end at a later time. For the crank, my impression is that a hi-performance reed valve flowed kinda crank wouldn't do much for the 20/20 carb and dinky stock reed valve. Just a reliable one. I like to ride more than tinker. I don't mind putting in time and effort, it's just less fun when it's unpredictable.

Any thoughts on a crank?

Are new bearings actually better or are they just the same stuff in a different box?

Thanks.

Delete me

Last edited by Christopher_55934 on Mon May 16, 2022 3:54 pm; edited 2 times in total

Not all bearings are the same different brands etc. After having ruined a case half from a seized factory bearing, I would replace it, with a better name brand bearing. If a bearing seizes and spins in case it makes a mess of the hole.

As for the crankshaft I think your right, I've always got the impression, that the half a reed set is the bottle neck. Maybe a standard 60mm crankshaft nothing fancy?

If you're running a reed, get a 60mm bell crank.

Thanks. I know bell cranks are considered good for reeds valve engines. And 60mm because yer replacing it anyway so why not a few more almost free cc's. From reading up, the 60mm doesn't really add any tuning issues other than adjusting the deck height with a spacer. I was considering going with a Mazz long stroke crank because of budget and the assumption that the stock Stella reed, is really not much of a reed and wouldn't really get the good out of a better crank. Feel free to correct me.

I have been all over the place with this. I learned a lot getting the Stella going and riding it a bit. One is that the low hanging fruit of the tuning tree is just puh-lenty for me. A bike that will reach 60 easily, hold 55 all day and hit 70 on those rare times Im feeling froggy does it for me. As long as I can make it reliable.

Would a bell help much on factory Stella or LML half a set of reeds?

Deck height believe it or not depends, working on my LML motor with DR kit, a 60mm crankshaft would have put the squish where you wanted it.

A good kit well put together should reach most of your goals. People always talk about top speed etc. I'm more into a capable cruising speed, just something to think about.


Yup

I can probably answer any questions you might have.

I run an MMW Block with VForce4 reeds and a Polini PWK34 on my LML. I could probably run an even larger carb, given that it still runs better without an air filter than with one, but given that I already have insane power (26 HP) out of this motor, I don't want to break even more stuff than I already have over the years.

Older post from Chandler, when I was where you are.

That's with a BGM177, a P200 60mm Bell Crank, a SIP RoadXL, SIP variable timing ignition, and a whole bunch of porting. I have the PM Tuning pipe I got from the guy on ebay, but haven't done anything with it just yet.

I started my adventures with a DR177 and the Boysen reeds, then expanded the stock LML reed cage by cutting out the bar and widening the mouth along with a 24/24si and some Dremel work.

Next, I upgraded to a PWK 28 and the VForce reeds, then eventually to the PWK34. I upgraded to a 35mm manifold on the MMW block and am still using the VForce4 reeds.

it's a first kick start and a blast to ride. I couldn't ask for much more from a motor at this point

Right. Different kits change the rpm range where the engine makes its power. I think that's why so many people can love and hate the same kit. Some know what they are going to get and are happy, others are unpleasantly surprised.

For me, the difference in the power band of the Polini kit compared to stock seemed quite pronounced. From my reading, it seems like the Polini is on the mild end of the spectrum. I liked it. Different, but in a good way that I could get used to. The rpm/cht gauge is a good idea. More than likely, I was short shifting and lugging.

The good news is that I still agree with myself on those points

I can't say how much the bell would help with the stock reeds. I was already onto the VForce4's before I got the crank.

I'm still running basically that same config as I was back then, only with the PM Tuning pipe, and it will cruise at about 75 MPH, probably more, but that's actually plenty of speed for me.

I put the SIP RoadXL back on at one point last summer, but never really put in the effort to get it sorted and went back to the JL. If I'm ever not so backlogged with future project work, I might revisit that decision, though, just for the noise factor.

As I noted in my original posts, one big advantage of the 60mm crank is that it gives you the ability to manage your port timings and squish without needing a machinist. The extra cc's are almost a nice-to-have as compared to that added control of your setup.

And there's only so much you can do with that original Stella reed block. If you want to see more on that, check out my Porting 101 or Blake7even's Sprint Sleeper thread, which I basically followed in the footsteps of when I was first getting started with tuning.

I'm pretty sure I could get 20 HP out of an LML reed block at this point, but it'd basically be doing it to see if I could, not because there's any actual point to it from my perspective. I'd basically be taking a build that *could* do more and restricting it through that little reed. That's a lot of work just to keep autolube when I could get the same thing, only much better, with a P200 motor.

As to getting to 70 on a Stella, you're building a rev monster, which that reed block won't support, and you're going to need a significant upgear (65+ primary and 22t or 23t clutch), plus the power to push it that fast, to make that happen.

Malossi 166 cast iron kit with long stroke and stock reed block gets 70+ with the 22t clutch gear and stock 68t primary. Cruises at 50 comfortably with tons of torque. I'm gonna replace the road xl pipe though since its rattling and dented to all hell. Not sure with what yet though.

Oh and BTW, thats on a 24/24 auto lube carb!

I'm in the process of building my 2nd stella with 128/195 timings and that same pm tuning pipe you have (ordered a pipe designs pipe in dec.. but never heard back from the guy once he said he would do it).. and I want to see if I can get away with using a 26/26 auto lube carb! At least for a while until I can afford the 800-1000 to convert it over to a 35mm side draft carb with all the additional v-force reed block parts.

Other than the rotary and a Road 2.0 rather than reed & RoadXL, this is basically my build on the SprintV motor I've put in my VBB, and it hits 65 MPH on 8's.

It's not that expensive to get started, MRP block top you can replace for various diameter carburetors.

https://www.mrp-racing.de/MRP-Reed-Valve-System-for-LML-engine-case-30mm-complete-set-with-RD350-reed-and-carb-rubber


Name brand Polini 30mm carburetor.
https://www.treatland.tv/polini-PWK-30mm-carburetor-p/polini-PWK-201.0169.htm?gclid=EAIaIQobChMIkpPAmPHm9wIVF_jICh3SGQyMEAQYCCABEgKS4fD_BwE

Your in for less than $400.00, and get rid of the half a reed setup.

Those are good suggestions. I'm trying to not get in over my head in terms of time, money and skill level. It would also suck to break spendy parts trying to punch above my weight.

Just to refresh, the engine in the Stella is

Polini 177
20/20 carb
22t clutch cog
FA Italia clutch
Sip Road 2
Stock LML everything else
Boyesen 2 stage reeds

I liked how it rode and it seems to be a fairly straightforward build…maybe on the old school side compared to what's available now…

I don't know if it would actually do 70, but even if it did, I doubt I'd be spending much time there so that is less of a consideration for me. 55 on a scooter feels fast for me, but I know that will change with more experience.

I feel a bit like I'm back where I started. I was just going to get the Stella going for the summer as is as a beater while I worked on the 200…the real star of the show. Turns out that it took longer than expected to sort it out and…I like it. With the brakes and wiring freshened up, cables lubed, etc. there is nothing lesser than about it. Badges don't get you down the road.

So I'm just considering doing the same build with the addition of a long stroke crank. Just going through the boring bits like bearings and seals to start fresh. I may also start with a fresh Polini kit or rebore and put in the next oversize depending on the time money ass ache equation. I would also consider a different kit, but with a similar power band.

I want to use it for:

Long trips
2 lane state highways or county routes
Get home again
Not worry

Add speed limits and desired cruising speeds to highways and county roads. Hardest part for me was finding a setup, that will cruise at an honest 60mph.

People can be like "I CAN GO 70 MPH" leaving out, I was tucked going down hill in the most uncomfortable position possible or on perfectly flat ground and it took me 1/2 mile to get there. It's like bragging rights or who caught biggest fish. That same setup on a small grade would slow to 45 mph and require shifting down a gear, power band is from 9000-9200 rpm.

Tubeless tires and rims help with long trips and getting home. You can plug a tubeless tire with a slow leak, a tube tire can blow out.

That P200 motor will bolt up and run in Stella, I would spend money fixing P200 motor and put it in. Cylinder kit and 60mm crankshaft will get you to 220cc ish. Basically your getting 40cc more or a 20% bigger displacement motor. I wish I had done that to mine originally and not wasted time and money on my 177 motor. Installed a P200 with a kit 225 kit and it met all my goals without doing any more work to it.

The limit of the Polini is the 2mm rings, which limit your max RPM's just just under 8,000. Estimate your top speed accordingly.

With your current/proposed setup, cruising at 60-ish MPH should be quite do-able without feeling like you're totally wringing out the motor. Just wringing it out a little bit. The Polini has a nice wide power bad and plays well with the Road 2.

The long stroke is not strictly necessary in your case, but will give you a little more low-end power if you think you need it. Your current setup should be straightforward to get running and reliable, which it sounds like is your main priority right now since the weather is nice.

Were you able to source new rings for the Polini?

It is only mid-May. You still have 5 1/2 months of good scooting weather left. If it was me, I would pop in the new rings, jet it correctly, and ride it like I stole it until the weather gets too cold. The Polini is not designed to maiximize top speeds but, since you already have the 22 tooth clutch, it should have no problem cruising at 60 and hitting 65 when you get the urge and the stars are properly aligned. As you will soon see, Vespa/LML did not intend for these things to go any faster than that anyway.

I haven't been able to find rings for the Polini in the states. and Either way, I would save that kit as it's in decent shape.

I considered throwing the P200 lump in, even just to try it out. It has low miles on it and was recently resealed. The only thing I'm unsure of is the wiring. The Stella has a Ducati CDI mounted to the to the battery side. Could I swap in the Stella stator and just plug it in?

You may have to swallow hard to stomach the price, but Scooterworks says they have them.

https://www.scooterworks.com/Piston-Ring-177-cc-kit-63-mm-standard-Polini

Thanks!

I converted mine to a Ducati CDI that mounts on motor and used P200 stator. Stator has three wires that run to CDI from motor no other wires needed to run it. Stella regulator only needs a single AC wire from stator to regulator to charge.

Thanks for this Christopher. I'm gonna file this info away for the future

Thank you. That's good to know That doesn't sound too hard. I might give it a try.

It really wasn't bad at all, only ignition wire that isn't connected if you use cdi on motor is kill switch wire. That's how people start and run these motors so easily on a stand. For kill switch wire I looked at wiring schematic, identified kill switch wire on Stella cdi under left panel pulled it loose and connected it to a wire that was already running over to motor I was no longer using, didn't even have to run a new wire there. If I ever put my LML motor back in for some reason I'll use a motor mounted CDI. I completely removed Stella CDI and wiring and it's sitting in a box of used scooter parts.

Gotta love a machine where an engine from the 2000's can be stabbed into a chassis from the early 60's. It opens up a lot of options and possibilities, which can be a blessing and a curse.

If a zombie apocalypse was on the horizon, I would have enough parts kicking around to put all 3 of us on a scooter and on the road to…well there's really nowhere to go.

But wow, so many options you can end up sitting in a pile of parts like a toddler in a sandbox full of Tonka trucks and hot wheels cars. Not that that's a bad thing.

I had a helpful talk with Matt at Scooter Mercato about the order I'm putting together. He had looked at my photos and said that the big end crank bearing had failed. He was really helpful with choosing parts and suggestions for jetting.

So I'm going with a long stroke mazz crank and Stella rebuild kit to replace the bearings and seals with better quality parts. I will be sticking with the Polini kit as it is still in good shape and I liked it. I might freshen up the cylinder with a light hone. Glad I got one good ride in because I know what I'm building will work out fine for me.

I was considering stuffing the 200 engine in, but I think that would just have me going in circles. Last night I started removing the bearings from the spare Stella engine. I got the selector box bearing out by getting the needle bearings out first which gives a good surface to drift on without messing up the case. A little heat and it wasn't too bad. There is a good FMP video that goes over what to replace in the LML engine to bring it up to PX standards.

Anyway, moving forward hopefully.

Got all but one bearing out. I have to pick up some better snap ring pliers so I can remove the drive shaft bearing. Heating the case with a heat gun and drifting out with a socket has worked fine. The only factory tool I have is the case splitter which also is used to gently push out the crank.

I was looking over the photos I sent to Scooter Mercato. There are some bits of debris all around the crank I thought were carbon, but they are probably bits of the crank bearing. Surprising that it started right up and got me 3 miles to home at 45 mph.

The 200 engine will probably get a rebuild at some point. 1 engine, 1 bike at a time. These things can seize when stuff breaks. It's the second time it's happened to me and I didn't enjoy it either time. Riding with an iffy engine also cuts into my ability to enjoy the ride. Besides that, the damage can wipe out a lot of spendy parts.

I have waited 32 years to get back on a Vespa. Waiting a few weeks more to build a safe and reliable engine is an insignificant delay.

Bearings are out. Kind of a big deal for me as I have never done this before. A bit nerve wracking, but a little heat and going slow and easy got it done.

Yes only one engine apart at a table me on the bench! You're doing it right.

Wow, you are committed! So sorry to hear the crank let go, I suppose that's pretty common on these. Didn't want to just swap in the other LmL engine for the season? I did do seals on that one.

I dragged the Rally out today and all my 2yr old did was ask about the blue scooter🤦‍♂️. I'm going to rebuild the rally engine this summer/winter.

Anyway, glad to see you haven't lost your determination!

I thought of just throwing it in. Unlikely that I would break an LML crank in one season or maybe ever. I just wanted to start fresh with something I had gone through myself. No offense. The engine seems to have pretty low miles.

I was thinking that I might just throw the 200 engine in after all, while waiting for parts and building the Stella engine.

I was looking at the stators last night and thinking I could put the LML stator in the 200. If not, the wiring should be pretty straightforward. I will leak test it on the bench too. It's all cleaned up with a rebuilt carb. Should be ready to go.

I have been always been curious about the 200 engines as I have never ridden with one. It has a 24/24 carb a SIP road 2. The jug looks huge.

Will this work? Thanks.


LML 2t stator

P200e Stator

P200e wires