quick carb help??? for christmas present

[readyon3]

I bought my son a 99 trx90 a few weeks ago, when I got it, it would not idle, but ran fine if you would just kep it running. I've been working on the plastic, painting frame, and fixing brakes, getting new wheels and tires ect, ect. I rebuilt the carb and cleaned out the gas tank and replaced the dry-rotted fuel lines tonite after work. The carb was very dirty, it looked like it had soggy cornbread all in it. I disassembled the entire thing cleaned everything very well and replaced the needle, all the jets, the float valve, gaskets and o-rings, everything that came with the kit. Got it started up and it would not idle, i turned the idle screw out and it started idleing but wouldn't come off of idle very well when you pushed the gas. It wanted to stumble and would cut off if you didn't press it slowly. I have the needle clip on the middle position and have the screw beside the idle screw (don't know what you call it, air screw or fuel screw) turned one and a half turns out, thats what the origional one was set at. The airbox lid is on but the restrictor is removed, and it has stock exhaust. Any help would be greatly appreciated. Tommorrow is the only day I'll be able to work on it before we give it to him for christmas. He's going to be very excited, he already has a suzuki JR 50 dirt bike and has been wanting a four wheeler ever since I got my 450r. I would love to have it running as good as possible before he gets it. Thanks in advance, Billy

[swamp]

maybe try picking the needle up all the way and the air screw maybe one more turn.... i have a stock carb i could have sent you if you would have given me more time........

[readyon3]

Originally posted by swamp
maybe try picking the needle up all the way and the air screw maybe one more turn.... i have a stock carb i could have sent you if you would have given me more time........

I'll try that in the morning, I haven't moved the needle but I've tried adjusting the air screw anywhere from 2 1/2 turns out to all the way in. At about 2 turns out it seemed like it would come off of idle better but after it would idle just a few seconds it would kinda choke down and cut off.

[swamp]

so will it idle at all now

[readyon3]

I can't get it to idle at all now. I can get it to idle very high but when yo put it in gear it chokes off. I can get it to run good and not idle or I can get it to idle really high and not run good. I've tried every needle position, and adjusting the air screw every which way to no avail. I'm still trying though, thanks for all the help so far.

[readyon3]

OK, started getting desperate, I changed the air screw, spring and o-ring back to the origional ones, turned it one and a half turns out and it started right up and was idleing. Ended up with the air screw about two turns out and had to adjust the idle screw some and it was idleing perfect, got on it put it in gear and it stayed running. Gave it about 1/2 throttle and it started going but was surging, bogging and just running awful. I let off the gas and it went back to a great idle. So now it idles but just doesn't run very well. Do I need to adjust the needle now or what? I would hate to adjust the needle and then couldn't get it to idle again. Thanks, Billy

[swamp]

it sounds like the little jet in there is still stopped up....Man your best bet and i no it sucks is to buy a new carb..........Not from honda way to much mulla

[Arctic Cat Dad]

when was the last time the top end was rebuilt? Kinda sounds to me like it may be to rich,and if the rings are shot it will run rich just a thought.

[readyon3]

Originally posted by swamp
it sounds like the little jet in there is still stopped up....Man your best bet and i no it sucks is to buy a new carb..........Not from honda way to much mulla

I don't mind buying a new carb, I just don't know what to buy. A 20mm, 22mm mikuni??? Future plans for the 90 include exhaust, uni filter, and maybe a high comp piston and cam, but that will all be farther down the road. If somone could point me in the right direction for a carb that would be greatly appreciated. I gave it to him on christmas, it was sitting in the driveway idleing when he came out of the house, he got to ride it for an hour or so, it wasn't running very well but he was still very excited, so hopefully I can have it running right soon.

[readyon3]

Originally posted by Arctic Cat Dad
when was the last time the top end was rebuilt? Kinda sounds to me like it may be to rich,and if the rings are shot it will run rich just a thought.

I don't think it has ever been gone through. It's probably all origional. Anyone know what the compression should be on it? I'll be getting a service manual for it very soon. Thanks