TRX 250X 280 kit

[steve]

i have a 92 250x and it has lone star axle, k/n filter, DMC exhaust and k/n jet kit. Ok i was wanting to know does the 280 big bore kit give a lot of power, is it worth it power wise. Please give me your imput, Thanks.

[BLURR250X]

I have the same quad as you but I'm thinking about either doing a 350X conversion or building a 330 stroker.If I'm gonna go through all the trouble of boreing a motor and all the other stuff that goes with it I want something that will rip.I'm sure a 280 is much better than stock but I personally wouldn't reccommend it.Although if you're looking for reliability then go with the 280.

[steve]

where can you get the 280 kit
do you know any web sites that have it or some specs on the kit
thanks

[MXQUAD294]

I have an 80mm big bore(290cc) in my '87 X. I got it from TC Racing. It was $295 about a year and a half ago. It came with a custom 12.5:1 piston and the sleeve. I had the stock sleeve bored .80" over (@260cc) with a 12:1 piston before I did the big bore. There is no comparison between the two- the big bore absolutely rips. I went from near back of the pack to top 5 on starts in the air cooled class at the nationals. If you've got a 250X don't be afraid to put a little money in it- they can run with a lot of the modified 400EX etc. I'll post some pics of mine when I get it back together.

[300exracer]

Will a modded 300ex do the same to a 400ex. Thats cool
:D

[nismo]

so the 250x's are good for modding? i have frame stuff on mine right now getting to the motor soon. how fast do u think a 250x will go with a big bore 290? and how fast is it with the 350x? i am trying to find a 350x for cheap in a barn or junk yard b/c i have had problems with my 250x motor (the trans was replaced and something is wrong that i havent figured out yet). thanx shaun

[MXQUAD294]

The 350X engine will have quite a bit more power than a 250X with similar mods or stock for that matter. But I have ridden a 350X conversion (in a 250X frame) and the 350X felt alot heavier to me. I think the only mods to the 350X I rode were a pipe and filter. It didn't seem to have as much bottom end power as my 250X- this was before I put the big bore in. The extra weight from the motor might have made it feel like it had less power. On the plus side the 350X does have 6 gears. But another thing to keep in mind is back in 1998 when TC Racing built the first 400cc Pro class four stroke-this was before the YZ400F found its way into a quad frame, he used the bottom end out of a 300EX and slapped a 350X head on it. I don't really know why he didn't use a complete 350X motor- my guess would be the extra weight of the 350X.

[BLURR250X]

I'm trying to decide which would be the smarter route: build a 330 or put a 350X motor in?Anyone?

[250xman]

im rebuilding my quad next weekend and i was wondering what jetting is any one running for a 288cc FST big bore kit? iim just tryin to gert an idea here so if you have a segestion let me have it!

[mitch250x]

If you have an 11:1 piston do you have to run high octane fuel?

[thelegendarycd]

mxquad294-did you notice a big difference from stock to the .80 over? i'm doing this now and i wanna know how much i'm gonna feel. thanks