300 Hp Wild Engine Rebuild!?!?
 

Hi and thanks in advance for your help and reading. I just had my quad at the shop for a rejetting and the motor siezed up on the dyno! :( Not sure whats happened yet but I wanted to see if anyone has rebuilt a motor on one of these quads? Mine is a 2002 model. If anyone has built one of these motors I'd really appreciate any insight on what I should do with mine! I'm curious if a bigger bore kit is available or stroker kit? Even if there are some tips on making my rebuild better or mine go faster than stock that'd be great to know. Again Thanks!!

Not too many quad riders here. I think the motor is very similar to the 300 from the bikes so any guidance there will help. Search the threads, someone posted a link to a full rebuild a while back. Also downoad the 2006 service manual.

A couple of other thoughts.

Check jetting for a more aggressive setting, i.e. using the triple taper needles (N1EF)

Check gearing if you want top speed. A smaller rear sprocket will help accomplish this.

You may want to jet a quad a bit richer than an EC300, all else being equal. More load on a quad motor. Consider this when looking at jetting specs for the bikes.

I remember when I had a Cannondale E440, the fuel/ignition maps were different for the 440 quads and you were advised not to run a bike map in a quad.