I have a 1989 trx250R. I was thinking of putting a 310 kit on it with the power valve or maybe putting a cr250 engine because of the better port Designs and power valve or a cr500 engine but that does't have a power valve or a harmonic balancer. Does anyone have any suggsions to what is better as far as hp or what fits easer or does anyone know of anything that might be better that what i have listed here that is two stroke... I do mostly lots of fast woods riding, flat tracking/ice racing...thanks

 

Do the 310. Dirt bike motors just arnt the same. Been there, done that, cheaply might have been the problem.[img]i/expressions/face-icon-small-smile.gif[/img]

 

of u are ganna get a 310 kit, get it from ERS (the best) and for ONLY 50 MORE u can get a 330 kit

something to think about

 

I agree.
Stay away from the motorcylce engines. They vibrate too much!

ESR does make some nice big bores from what I've heard.

You can also have a credible engine builder do some work on your existing motor.

 

The 310 kits are all the same, made by pro X. Different companies just put their name on it and do some slight porting enough to call it their own.

Just buy a 310 kit UNPORTED and then send it to a reputable engine builder and have it ported correctly

I once had a "trinity stage IV piece of sh-t" cylinder and I would have done better by flushing my money down the toilet. I kept looking for the flush handle on my trinity cylinder. LOL.........

 

I have a 310 on mine and it has awesome power.

 

im eagerly waiting for my 350 power valve from CT... hopefully next week [img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-cool.gif[/img]