I have a 1992 TRX 250X that has a FMF power core 4 and a k&n air filter. I want it to be a little faster for not much money. Yet it will still beat a 300EX I want a little more speed and power.

 

Cut 4 1/2 inch holes in your air box and re-jet the carb if needed. Install a higher compression piston somewhere around 10:1 or 10.5:1 and you can still use pump gas. CT racing sells a drop in cam that's a little wilder then stock. Another option is you can also change your gearing i.e. larger countershaft sproket and smaller rear.Also try an aftermarket header, the one on the X and EX are very restrictive. These mod's shouldnt run you over $350 (don't quote me on this it's just a guess) and i know you wont be dissapointed.

 

First, sell the power core 4... they're completely junk. The dynos dirt wheels did prove it too. Then get something like a White Bros. Don't get a Cobra cheapo pipe like mine...mines not too bad... i out-run 300ex's but i still don't like the pipe. And what he said.

 

I'D say sell the power core 4 they are junk , or if you dont want to but another pipe at least take the discs and spark arester out, drill holes in your air box and rejet if you have to, i dont know what size tire you have but a smaller and lighter tire wont bog you down as much as a large tire.

 

put a 350x motor in it, WHOA! u'll beat some 400ex's!

 

depends on what you mean as cheap

you can go

90 for hi comp piston
90 for cam

That will be good

or you can go a little more

get the piston and the cam.

you could even bore it as much as 2mm without resleeving..and get a lil more displacement

 

Call TC racing or Curtis Sparks they can hook you up from mild to wild (+5hp to +35hp) it depends on what you want to spend