Scoring on new olympia 43mm kit -- vespa grande

emanuel gountoumas /

Hey everybody, i've been reading old forums and decided its about time I make my own post. I've got a vespa grande I put a new kit on and broke it in for about 100 miles. I just took it apart and noticed scoring on the cylinder and piston and do not know what is causing this or what I should do. Any help would be appreciated. The bike is stock besides a malossi air filter and a 56 jet on the sha 12.12 carb.

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Re: Scoring on new olympia 43mm kit -- vespa grande

Looks like it soft seized from getting too hot. Either your a little lean, have a air leak at a gasket or the crankshaft seal.

Re: Scoring on new olympia 43mm kit -- vespa grande

emanuel gountoumas /

is the cylinder/piston toast in the long run now?

Re: Scoring on new olympia 43mm kit -- vespa grande

I wish my piston looked even close to that good .

I've been running a piston in much worse condition than that for years .

I just bought a replacement set , but , it's more for if the current set gets too far gone .

Re: Scoring on new olympia 43mm kit -- vespa grande

> emanuel gountoumas Wrote:

> -------------------------------------------------------

> is the cylinder/piston toast in the long run now?

Just lightly sand the marks smooth they and you'll be good to go.

Re: Scoring on new olympia 43mm kit -- vespa grande

emanuel gountoumas /

what grit should i use?

Re: Scoring on new olympia 43mm kit -- vespa grande

Dirty30 Dillon /

In the event that you're running your all your shrouds (cylinder top and fan) than you're lean. If you don't sus out the lean issue, be it poor fan cooling, untuned carb, or airleak, you're going to continue doing this.

Re: Scoring on new olympia 43mm kit -- vespa grande

Did you use the stock head? Id Lap the head and cylinder, check for airleaks and jet up to mid 60's

Re: Scoring on new olympia 43mm kit -- vespa grande

Jack Rutherford /

check your piston to cylinder wall clearance against specs. Of course, if it is a kit then you won't have anything to check against unless there is some general guideline in the wiki for clearance based upon bore and piston size. If you don't think you are running lean then I think the piston is slightly too big for the cylinder or the cylinder is slightly too small for the piston. I've had similar thing happen with similar "scoring" in similar place. I don't think it was from running lean.

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