Originally Posted by Jonro

I don't think its worth replacing the piston and sleeve on a V-spec because of the price that they are sold at you may as well be buying a new engine.

OP, if you do need to buy a new engine, do a bit of searching around and i suggest getting a GRP MR tuned promokit. These can be found surprising very cheap from Hong Kong sellers. And they are pretty much the Lamborghini of RC engines.