will a 400ex or a 250r or a 400ex black baox fit on my 300ex

 

Our 12:1 compression is not actual but estimated. The piston is for a 250x and is either a 13:1 or 11:1 for it. (250x) A friend had the piston brand new and no longer had the bike. He gave us the piston and we checked with Weisco to see if it would work. Weisco told me that if it has had no head work done, it should be about 12:1. (in the 300) The piston has a HUGE dome on its top compared to the stocker. I was afraid it would have to run on race fuel, but I started it off on good 93, with octane booster. Over time, we stopped using the booster and it does not seem to effect it at all.

 

I'm not 100% sure on this but i think the stock rev limiter is set for 8,300 rpm and a moddified rev limiter is set at 9,300rpm. or it could be 7,300 and 8,300? if anybody knows for sure please post. You might be able to find it by doing a search in this forum.

 

hey guys does any1 kmow if a 400ex black box will work?!??!?

 

here are some threads discussing black boxes and rev limiters for the 300ex

click

click2

 

thx semms but daoes anyone know were i can get a black box for cheap or if any other atv black boxes workon a 300ex