Carbon buildup 1980 P200e

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Sat Sep 12, 2020 2:23 am

My 1980 Vespa P200e has almost 26,000 miles now, up from about 20,000 when I bought it a few years ago. Read somewhere about carbon buildup in two cycle systems - even including a muffler carbon burnout.

So I’ve been wondering how concerned I should be about possible carbon buikdup in this Vespa. Swapping in a new muffler would not be too difficult. The thoughts of disassembling the engine (or hiring it done) is frightening.

Presently it is a struggle to get from 45 to 50 miles per hour. Wondering how much improvement I might expect from replacing the muffler. And how much more might be available from decarbonizing the head, piston, cylinder and its ports.

Thanks for your input.

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Sat Sep 12, 2020 7:08 am

With lack of power i'd be checking/replacing the piston rings........whilst doing this remove excess carbon if an issue.

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Sat Sep 12, 2020 12:05 pm

AS above, 26k miles is a looong way and it will be well overdue a major service. Modern 2 stroke oil is usually 'low ash' so doesnt carbon up as much as the old mineral oil but you will have no idea what oil has been used in the past and I would expect a significant build up even with modern oils at that mileage. Also as said ring replacement is a certainty and possibly even a new piston. Cleaning the muffler will involve plugging the tail pipe and filling it with caustic soda, not a pleasant job and probably better to fit a new one. The difference after getting that done will be staggering.

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Sat Sep 26, 2020 8:04 am

It's crying out for a rebore, a SIP Road 2 and a filter modification......

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Sun Sep 27, 2020 10:48 am

It’s not hard to decoke and replace the rings.
Or even get it rebore with new piston if the bore is worn.

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