Modern Vespa

I am planning to move an 'as new' but 20 year old PX200 engine into a PX150. Objective is daily ride with a little extra. The 200 engine is totally stock and unused, and I have no intention of splitting it, unless I discover that the original seals are shot. Should I:

1. Leave it exactly as it is?

2. Pop on a Polini box and upjet accordingly? I have the parts I need

3. Pop on a NOS Malossi 210 + Malossi head from an MHR 57mm kit + Polini box + upjet? The piston has been fully worked but no cylinder port work has been done. The kit has only been used for a few short test/jetting rides on another engine.

If I don't split the case (my preferred route), I won't get to change the 4th gear cog to a 36T. This may not suit the old skool 210 kit.

I'd do option #1 until you get motor running good and verify it's tight.

Then

Slip on your choice of exhaust, up jet a bit.

Then

You can slip on 210 kit if you want.

Thanks Christopher. I'm inclined to agree. One thing I don't want to do is compromise such a great engine in any way, and I'm kind of liking the idea of stock+. I have two others that I've ported, kitted, longstroked etc. Maybe I just enjoy this one as Piaggio intended

personally, I'd knock some seals in it straight away. it's out and it's on the bench so why not take a leisurely afternoon and knock it out.

from there I'd only do reliability and enhancement work. port and match the cylinder, polish the piston crown and exhaust, match the carb and carb box, drill the carb and filter, maybe lighten the flywheel. nothing radical.

obviously you'll want to address the clutch. if standard, upgrade to cosa. otherwise springs and plates and call it.

but I'm in your camp, knock on that SIP pipe and roll.

Thanks Greasy. It's a 2001/02 PX200 elestart motor, so it has a Cosa clutch from the factory. It would be a shame to split the engine, at least for the first several thousands of miles, as it's never had a wrench near it, apart from an annual gearbox oil change. I did start and idle the engine every couple of weeks or so whilst it was in the original bike. I suppose I could pressure test it when it's on the bench and take it from there. It will have the factory (black?) Rolf crankshaft seals in there, so they may have succumbed to 5% ethanol during the periodic engine runs over the years.

Does the "it's only original once" mantra apply to engines, or just bodywork and paint?

If it was mine, I'd be leaning towards 3.

But, no need for porting and flowing.

I'd aim for decent port timing for the exhaust and call it a day.

Then again, if the engine isn't in bad shape and is fairly stock, 2. might be a good idea if tuning isn't high on the agenda.

Seems a shame to pull an original apart.

Ride it until you realise it's not powerful enough or the seals go… whichever comes first.

But then I'd be replacing it with the 125-150 engine tuned with a 187cc kit

If it were mine, I'd do exactly what Greasy said.

I'm approaching this from an entirely CYA viewpoint. as somebody that does this for a living, I'd do the seals. as somebody that is a lazy asshole with their own bikes? I totally would not and just install it and roll. but at somebody that will take advantage of, like having one out? well, what's a ballgame and a few beers and like $40 in parts for peace of mind?

but, as your lawyer, I'd suggest if you got it on the bench... split it and knock some seals in. freshen up those clutch plates, and do ALL the o-rings and call it done. also, rent a very fast car with out a top. get the fuck out of dodge. and drugs. you'll need all the drugs.

it's only OG once does not pertain to motors. how many virgins you slept with were a good time?

and you're kicking that fucker eight ways from Sunday at 3 am when you come out of the club and it STILL won't start and the cutie-cupcake gal with the sideways bangs decides to leave with her gal-pal instead.

I know this story well, friend.

fortune may favor the brave, but luck rides with those who are prepared!


do the seals

According to the PO of my 77 p200e, he acquired the bike with 1,300 original miles on the clock and it sucked up the clutch side seal and did a number on the rotary pad and crank. He ended up having to replace the crank and JB weld the scoring on the rotary pad. I don't know if this was a particular issue for those engines. His thread is in here somewhere.

He also put on a SIP road 2 and upjetted accordingly. I haven't gotten it running yet but my impression is that his 177 Polini kitted Stella was quicker. He seemed a little underwhelmed by the 200. I have also considered the Malossi 210 kit, but as a beginner, am opting to just start by getting what I have to be a solid running bike before I start tinkering.

If anyone is picking up ladies on a PX, I think they have bigger problems than which engine to install and a scooter which won't start…

J/king…

But sticking the engine in, having the seals blow and then redoing the engine at that point seems reasonable… busted crank, rotary pad and stock cylinder will be the damage… if the Malossi goes on, it's a 19-20HP explosion…

Like CM says, "it's an adventure"

I also say no performance parts other than the exhaust. Seals, plates, cruciform, then polish & flow where it needs it, but past that, I'd even leave the Malossi on the shelf since you need to relocate a transfer for that kit.

If it were me, I'd get my transfers up to like 122 or 123 for the Polini, exhaust to 170, and go.

Squish is probably going to be the biggest challenge unless you can easily get the cylinder milled down a couple mm.

If you want to ride a fast bike, you already have those. An E-start P200 is an excellent option for a daily rider and just blueprinting it a little will get it to a good place without compromising reliability.

This is definitely not one of my options. I'm obsessed with 2xx engines. If I wanted to throw money at it, a Malossi 210 Sport would be the obvious choice. My three options at this stage involve an excellent base engine, parts that I have on the shelf, and quite possibly a new set of seals, 'o' rings and gaskets.

What we need is a BGM 177 style head for the stock 200 cylinder!

Indeed! That would be one of the Best. Things. Ever.

Maybe I could persuade you otherwise…????

It actually works out cheaper than a 210, the kit has the reeds and manifold included

A vote for the yuppie kit. It's a nice, modest boost of power while still being simple and reliable... #2

I'm #2 also, but keep an eye on those seals. Don't want to be stranded while picking up the cutie cupcake gal like Greasy said.

On second thought, if it's on the bench, do EXACTLY what Greasy said.

I've got a 79 P200 with over 10k miles on a non-opened engine also. When that engine comes out, it's gonna get seals, bearings, cush rebuild, and possibly a 60mm crank. The top end? To be determined......

I didn't read other replies, sorry... my thoughts: go with #1, then once you want more out of it go hard!

If voting is still open I'm in camp #2, but you're gonna wanna do those seals and check the internals, so I'd split the cases and look for wear items while replacing seals.

There won't be any worn items John as it's a brand new [20 year old] motor. It's the rubber seals and possibly clutch friction plates that concern me, as they may have perished/deteriorated, despite the lack of use. I'm going to get the motor out and onto the bench Saturday. Will pressure test, and if it holds up, I'll leave it be for the time being. Gonna keep this one 98% stock for posterity, with just a Polini box (or SIP Road 3), and the necessary upjet.

fair enough! the seals could go quick but the hard parts should be fine then. A pressure test is always a good idea, and could at least give you some confidence.

I 100% expect the clutch corks to be waxed.

the seals might be negligible, and the gaskets fine. but you're gonna wind up doing those seals sooner rather than later.

either way, order up a new set of corks. that way you've got them on hand.