Anybody know what other motors will fit a 2003 TRX 300 EX without too many mods. Any body ever do this or know any one who has.

Thanks

 

87-92 Honda250X
93-08 Honda300EX
03-07 Addly Interceptor 300

Those are"boltin"engines.

The 350X bolts in after you remove a small portion of the rear engine case with a hacksaw and can fabricate an exhaust and intake tract. Powroll offers kits making it a more true "bolt on" experience. THIS is the swap I would recommend you intend on keeping this quad a while to get your moneys worth. You will want to switch to better shocks and no less than a +2" swingarm to get the best of it.

Another engine swap I have seen alot of are the CMX/CB 250 parallel twin Honda street bike engines. Have no idea why considering they don't make but a couple ponies more than the 300EX engine and require a bit more work to get them fit.

I also seen a YZ400F engine in one at a club meet a few years back. He had a good deal of suspension and chassis mods to go along with it. Although I didnt ride it, the owner himself admited the chassis was not capable of ever being well suited to that engine. Too much can be enough in such a small package.