Jetting oversized trx 90 help

[quadracer707]

Ok guys her's what we got. I have a trx that we were trying to get a miss out of that I bought over the winter, ran pretty good. However took jetting apart, main jet, clip, fuel screw. I beleive we had an108 in main, not sure i have a 100 105 108 110 112, & clip & fuel screw everywere. Here is what we have done to quad, so maybe you experts can get me started somewhere. TRX 90 with a 115cc with poweroll stroker,200x carb, using a short uni filter, & a FMF powercore 4 pipe, and a modded cdi box.
What I need is main jet#, were to put clip top middle bottom, were to set Fuel screw, which is now 1&half turns out. Will check back in about an hour going to try some other combos,

Thanx Ken

[Mxjunkie]

What is the quad doing when it's running? Bubblering, sputtering? back firing?

Little more information will help! I can ask around to some of the local d6 mini guys out there and see if I can find out something on the combo you have there.

[quadracer707]

No back firing at all, at 1/4 throttle & up it totally looses power I guess like you say blubbering, half choke & full choke revs REAL fast & runs better, but 3/4 throttle starts blubbering. I am going to change spark plug again & put fresh gas in since this gas was left over from the season in the tank. Carb is completeley clean with no debris, Also quad fires right up on 1/2 choke but does have issues staying a nice idle, when i take choke off ,

Thanx Ken

[Mxjunkie]

Sounds like it needs more fuel at idle and the needle moved out of the jet to give it more fuel as it progresses across the RM range. If not so much the needle maybe a bigger main jet, when you change main jets always try the needle in the center postion and go from there, I had a hell of a time tuning my nephews trx awhile back they are mooody little mofos! hah

[quadracer707]

Still trying, UNREAL, thanx though,

Ken

[ROBBSRACING]

With that engine/carb set up I would think Needle 4th down, 38 pilot, 90 main jet and 1 1/4 on the air screw should be VERY close.

What cylinder head are you using ?

[quadracer707]

Thank you for your response, the cylinder head id stock with just a clean up on the ports, We ran it last year with a 108 & 35, now i dont know, so I will try that either later tonite or tomorrow,

thanx Ken

p.s. I was hoping you would respond

[quadracer707]

Mr robb,
Took your advice & it was aheck of alot closer,here is what i have it adjusted to38 pilot 90 main needle on 1st clip,leanest 3/4 airscrew. Here is what it is doing idle nice 1/4-1/2 nice 1/2-3/4 slite bog 3/4open bogs out, half choke it & runs good. Should i dropdown main pilot to next size, which i have to get dont know what that is or go up which is a 95??

And the sparkplug Iam using is a NGK 4549 cr7hsa, is that ok??

Little man excited I was actually able to take out on street to try it,

Thanx Ken

[ROBBSRACING]

I would try richening the needle 2 clips and up the main to the 95 then.

[quadracer707]

Ok rob here is what i did for the past 3 hours put 95 in 3rd notch bogged out alot 1/2-3/4 plus throtlle. clip 1& 2 Ran good upto 3/4 throttle clip 4&5 completeley sucked, put main of 100 105 108 basicly same thingruns good clip 1,2 somewhat 3 4& 5 suck, however if i ran 1/2 choke pretty good thru out choke, full choke wanted to run great but idle like it was going to blow up, any help appreciated, or anyone else,

Thanx Ken