86 trx250r

[rboyer]

Having some jetting issues...I am new to tHe site and I have jus gotten the 86 trx250r....let me get to the point...I think the top end is mostly stock.some porting I noticed. I have an lrd pipe and silencer. Vforce 3 reeds(new), k n filter, 32;1 w hp2 oil..I'm in south jersey ,so At sea level... The carb says pj38 and some other #s on the side of it. So I'm guessing it is a 38mm...I got the bike it had a 152main and 48 pilot..w the air screw 1/2 turn out...it had a br7 plug in it too (with leaky cranky seal)....I changed the plug to an 8 and it has a rich bogg now in the low end..if I snap the throttle from idle to wot....I have went to a 40 pilot and a 160 main...and it got a lil better..but the hesistation is still there..and its mushy down low..seems to run hot..I got a inline temp gauge for the antifreeze and it usually runs from 150- 180 on the inlet side..bottom hose out of the radiator..but the jug seems a lil hot...can hold my hand on it for a second or two when its hot....please help...do I need to trash the pj38...are the air strykers worth it?

[wilkin250r]

38mm is a pretty big on a stock motor. Not necessarily TOO big, a lot of people run them, but they're not for everybody.

Like everything else, carb size is a compromise. If you're trying to pull air through a small carb, it will have to flow much faster through a small opening than it will through a bigger carb and a bigger opening.

With less restriction, a bigger carb will let a little more air through, so will have better top-end power. But the higher airspeed of the smaller carb gives better jetting control, better fuel mixture in the mid-rpm range, and better throttle response.

[rboyer]

So should I downsize on the carb? I don't want to lose power up top tho...do I kinda have to chose one or the other?? Response or power?? The bike screams on top end and pulls very hard...thanks for the info and quick response time...

[wilkin250r]

The PWK carburetors have a different shape to the carb slide that will improve throttle response, and the Air Stryker versions have fins inside that channel airflow for even more improved throttle response.

A 38PWK Air Stryker might fix the problem enough that you can live with it. It still won't be quite as good as a smaller carb, but it might be the best compromise.

[rboyer]

AOk thanks...could I try and fix it with a pipe? I have a bills pipe that isn't as fat as my lrd and has a shorty silencer?? Or jus set up for top end and live w it? Does it make sense that when I had a larger main(rich) it pulled harder? Or is it jus my imagination? Any kind of jet set up to help topend power? Rich or deadon w a brown plug? Could new needle help it? I tried droppin the needle..bit got a bad rich bog when I raised it and a bad lean.bog w a lowered it 1 clip position either way...

[slamdak8782]

I put a 39 PWK airstryker on mine from the stock one and for me it was a world of difference. It does bog a little bit but you get used to it and my experience has been good with it just my 2 cents. I also had to change the main jet needle itself. They have different profile ones. For me changing that after getting close everywhere else made a huge difference down low. Someone might be able to point you in the right direction as far as taper goes but I think mine was a CEL taper. Stock jug and .020 over

[rboyer]

Thanks..I was thinking of changing it but it doesn't have any markings on the needle...I got it really close and that would of been my next step... I'm waiting for my choke/idle knob assembly....I bent it..tried to bend it back and it snaped...so the new one should be here teusday...it had some wear marks too...I was wondering if that had something to do with it....but if any one has a 38pj and had real good luck with a certain needle, I would def go out and get it an try it....I'm not sure of ther bore of the topend but it is a stock jug....any one have a 38pj and have luck with it???