250X question?

[bryan.young1]

if i put a slightly higher compression piston (12 to 1) and a all around cam into my stock 87 250X, would i NEED to rejet and up the exaust or could i just leave it at that. i guess i just want to know if it will hurt anything if i dont do this.

thanks
bryan

[wilkin250r]

Yes, you need to rejet.

If you don't know how to rejet, or don't know EXACTLY what you are doing and everything that is involved, you should either send it to a shop to do the whole thing for you (which will be expensive), or don't do it at all.

If you can't rejet your carb, or worse, don't know if you should be doing it or not, you should NOT be making upgrades on your engine.

[bryan.young1]

i ment if i had a shop do the cam and the piston would i need to up the jetting and the exaust so as not to damage anything. i dont want to mess with the exaust because i dont want it to loud and i would like to keep the jetting so im not using more gas and plus its all more money. i just wanted to get a bit more hp for my little 250.

thanks
bryan

[250xTrailRider]

I don't think the stock exhaust will hurt the engine. You would not see as big a performance gain from the cam and piston upgrade though. However if you do not increase your jet size and/or needle that could cause a lean condition which could burn things up. I would guess that if you got a webcams cam they would have a good recommendation for you. http://www.webcamshafts.com/honda-atv.html#10
I am sure that if you spoke to there tech they would have a recomendation on jet sizes and I would say that the 55-571 cam would be a great start. It looks like (to Me anyway) that one can make improvements over stock but still work with all the other stock pieces. If you go with a real radical cam you maybe into a lot of head work, springs, exhaust, new rocker arms. Carb work on the 250x is not overly hard if you take your time and don't get flustrated.

[bryan.young1]

thats what i was looking for. just something simple that would beef me up a bit without going crazy.

[250xTrailRider]

I would say get a Clymer manual as well. Not on the best seller list but it has great information.

[wilkin250r]

Your gas milage really won't change all that much.

Jetting is EXTREMELY important to keep your engine running properly. Too rich (too much fuel), and you'll foul plugs and get lots of carbon build-up inside your engine.

Too lean and you will overheat, possibly melt your piston or sieze your engine. Lean is VERY bad, rich is only slightly bad.

As a general rule, ANY time you make changes to the fuel, combustion exhaust path, check/change your jetting. This would include a filter, exhaust, carburetor, piston, camshaft, or even reeds in a 2-stroke. Anytime you change anything in the air/fuel path, you need to jet.

[bryan.young1]

how do i check my jetting to make sure im using the proper needle for my setup? just talk to who is doing the piston and cam work and ask them? the guy i bought the bike from put a white bros e series exaust on her and re jetted her for that. i the exaust off and put the stocker back on and have been running it like that ever since. i think he put just a slightly bigger jet in it.

thanks
bryan