Well i'm getting back into riding after a few years of no riding thanks to my nephews. Got a few questions.....

I have 2 lt 250 r's. I think one is a 91 but not sure since the tag has been worn off. Is there another place to find out what year? The other is an 88, I swapped the motors on them because the 88 motor had a new jug when i bought it and it was much stronger so I put it on the 91 which is in better overall shape.

They both have a Paul Turner pipe and Fat Boy silencer and a unifilter with the top off the stock airbox.

First I'd like to know how to go about setting the power valve to get max power.

Second, i'm not sure what all has been done to either one and will be looking into it but do aftermarket reeds really help out any?

The motor on the 88 (91 motor) I think needs a rebuild. I can tell just by kicking both that it has nowhere near the compression the other has plus it's not as fast in a drag race. What's a good piston to get? Was thinking wiseco .020 over.

Also, was thinking about shaving the head. How far can you take it down before you have to use race gas? I'm assuming you cant jack the compression up very much on pump gas due to the oil mixed in the gas, oil isnt very detonation friendly.

A buddy at work just got an 03 raptor with a K&N air filter and exhaust. I had to get it running for him last week, that thing has gobs of freakin tourqe. I'm a car guy, I know nothing about what works for 4 wheelers. We are going riding in a few weeks and i need to beat him, help me out here fellas.

 

So nobody knows anything about these 4 wheelers? Hmmm guess I joined the wrong site. [img]i/expressions/face-icon-small-disgusted.gif[/img]

 

Don't get frustrated, Xmas and all, people aren't postin like normal..
Hang in there I am sure someone will have answers for ya. Wish I could help but I BARELY qualify to talk about 4 strokes.[img]i/expressions/face-icon-small-happy.gif[/img]

 

No need to shave the head--a .20 over Wiseco or Arias pistons and a nice re-bore will do just fine. You may also want to consider an after-market head for improved cooling.

 

the lt250r isnt 4 stroke,
if its low on compression you will need to pull the jug and get it mic'ed to see where it is before you get the new piston, (if its already .20 over or if it has deep grooves it may need larger bore, or you may be able to get by just re-ringing it)
with 2 stroke motors the gains come from letting the motor breath better, pipe/intake and porting
03 raptor is the 660, they do run well but you can get by him (my trx250r use to pull my friends 660)