hop ups for atc 90/110 still made?

[hawaiirider]

are hop ups for either bike other than just a pipe air cleaner still made?
is it better to mod the stock motor or work with a crf 50 since theres sooo many mods available?
also will the e start off the 125 bolt on? can you fit 25 inch tires and last but not least is it possible to do some machining on the hi/lo range box and get a reverse gear? somebody told me they used to offet a kit??
thanks!!

[Vealmonkey]

hawaiirider wasn't this covered before? You can get a big bore piston and go about 125ccs. The crf 50 engine is a different size and you have to buy special parts just to get that engine to fit in an atc90/110 frame. The atc125 cylinder and piston won't fit an atc110. If you want an engine with reverse, why don't you just buy the engine with the reverse, but I don't think that will work with a chain driven engine. And a 125 e start won't bolt on.