Boring the a35/42L piston

Here is the deal,

I have been busy with my 94 Tomos Sprint. Currently I have a 27 tooth speed sproket, upped the main jet and added the one piece Bi turbo, and added a side stand. My research brought me to the Tomos page where they describe in full detail how to bore the stock a35 to a 60cc spec. Has anyone ever tried this? If so how much did it cost, where did you get it done and what is the current top speed? Also where do you buy a 42L piston as described in the tuning/bore section? Who makes it? How much is it, and where can you get one? Is this procedure worth it? Is it cheaper then the aftermarket 60cc "speed kit"?

Thanks for your response

Re: Boring the a35/42L piston

Reeperette /

I doubt it would be cheaper, and I am not sure they even make the 42L piston'd prolly have to find one at a swapmeet or something.

Not entirely sure, but I think perhaps wyseco made the 42L, don't take that as given tho, it's been a long time and memory fails...

I would either bore it to 38.5mm - cause you can get an Overbore Tomos Piston&Rings from the manufacturer...or just go aftermarket.

As far as aftermarket, there's both 60cc and 70cc kits, and the 70cc is much more cost-effective, although it has a reputation for unreliability and cannot be mounted to the A3 engine.

A3 - hexagonal cylinder, A5 - square cylinder....A35's kind of a misnomer.

Bullets have A3, Targa/Sprint has A5.

I'd be really leery of boring the original cylinder anywhere over 38.5mm - it's risky, in my opinion.


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