Modern Vespa

Hello

My px 200 went bang the other day, got it stripped down ready for new cylinder and piston. Really struggling to know what fits it?

Would be happy with just a standard px 200 kit due to cost.

It's currently got a Malossi in it, piston says 68.41

But unsure what crank or rod / size it has in it 🤔 could someone please help me what I need to put in it.

Thanks 😊

A few pics

Sorry can't seem to edit it yet as first post?

Pics here https://photos.app.goo.gl/JcWtDyFTkDM9mX4A9

Thanks you.

Moved to NSM.

I would not just throw a new cylinder in. Engine has been running pretty lean and seizing the cylinder is just a symptom of this. Cause of running lean has to be hunted down. I would do a pressure test on the engine to see if the bottom end is leak-proof. What jets are in your carb at the moment?

If your cylinder coating has not flaked off and piston rings have not snapped, you could get away with your current cylinder and piston too. Not optimal, but it will work without investing more money into it f you are on a budget. Also that Malossi is a lot nicer cylinder than the stock one.

You can use drain cleaner (Potassium hydroxide) to get the smeared aluminum off your cylinder walls. Small file, sandpaper and some patience should also get your rings unstuck and ring grooves cleaned.

I got away with this even though I had to weld the piston


And still made 15hp on the dyno

Tha ks for taking thr time and giving me the info, unfortunately thr cylinder is badly scored and the lining has been removed so it really need a new cylinder

can't seem to be able to edit.

What I'm struggling with is will a standard piston and cylinder just fit straight, it has a malossi cylinder and piston, maby conrod ect.

I'm thinking I may have to split the engine and measure length of the conrod ect.

I'm just thinking if I fit a new standard cylinder and piston it will hit the head maby ¿

Thanks

Stock cylinder will fit just fine. Malossi does not require the use of different conrod or crank.

Do a pressure test though.

Whatever 57mm cylinder you buy will fit. If you have a non standard crank it will just need a packer.

wowzers thanks very much for the help ive ordered a standard 200 kit