Modern Vespa

Read my "High Speed Stalling" thread below, then the update:

Pulled the carb, saw a jet needed to be swapped out and the fuel bowl had a lot of crap in it from someone not having put the filter screen on properly - I think.
I carefully looked down into the crank, and it looked pretty good. Nice and wet, but not to wet or too dry.
replaced the coil, pulled the spark plug, and noticed something weird. on the side of the plug, where the ground part comes out, was white, and the rest of the plug was chocolate. I did not know what to explain what was obviously a misshapen fireball, which means...
When I pull the head and first notice an absence of a gasket (?!?!) then the ugly truth - the bottom of the head showed signs of blow-by. and the scores in the cylinder means soft seize - several times actually. So I am concluding that maybe something worked its way loose, aided by the lack of a head gasket, and I get what I see. Well its a good thing I have a Malossi kit coming. I almost forgot the best part. the top of the head is a piaggio symbol and 150 stamped on it. the bike is a P125x. Odd?

I'll let others with more knowledgeable than I respond, but I do not believe there's supposed to be a gasket between the head and the cylinder. It's just torqued down, metal to metal. If there's blow-by perhaps the head wasn't properly torqued, or in the wrong order, causing warping...

A scratched cylinder wall and piston from siezes can only be fixed by boring out the cylinder and going up an oversize, but there's no need with your kit on the way...

Not sure about the Piaggo 150 stamp. Could it be a shared part? Did someone just install what they happened to have on hand? Might, in fact, someone have installed a 145cc or 149cc (like the P150X) cylinder, piston, and head on your scoot? The stroke is always 57mm, so it would probably be an easy replacement from the original 123.4cc jug, and both the P125X, P150X and even the much older Sprint Veloce all had the SI 20/20 carb so it would be easy to swap these parts around.

I didn't really expect the bike to be bone stock, and it is far from one of those Vietnam restoration jobs - way too ugly for that - but it was a bit of a surprise to see that somewhere in the past, someone stuck a 150 top kit on it (case number matches up to the 125)

Yeah there is no gasket there, so it was just torqued down wrong, or allowed to loosen. I have my 166 Malossi kit being prepped as we speak, so we will see.....