problem with my ATC 90..Any Suggestions ??

[ATC90JAY]

Hi! Im trying to get this 90 going cant wait to ride!!!!The problem I have is when I get my trike started it doesn't want to idle without the choke on and then when I give it throttle it revs up high and comes down slow or I have to adjust the choke...I replaced the carb and still the same problem....I did notice that the throttle cable is very tight so I have a new one that I'm going to put on would that cause that issue?. I also changed the spark plug..any thoughts on this?? Thanks, Jay

[shortline10]

Your small jet is clogged .

[ATC90JAY]

How do I fix?

[trike savior]

Sounds like the carb is not adjusted properly. definitely too small on idle jet. Where did you get replacement. If its a new ebay chinese replacement then it probably came with wrong jets in it. If it is an original piece then the old jets have too much tarnish and need to be chem dipped or replaced with new. It does not matter if you can see through the jets, the layer of tarnish can get think enough to make the jet act a size or 2 smaller. And that is enough to make it not idle, especially in cold weather.

Chem dip can be found at walmart in auto section by the starting fluid. Its a 1 gallon paint can with white label. soak for a day or 2.

if that does not work you need 1 size larger on idle jet

[kb0nly]

Sounds like nothing more than an air leak to me, bad gasket from replacing the carb and messing with it. New gaskets should fix it up.

[wisconsinite]

Check out the intake boot for cracks also...

[trike savior]

also good points. the intake tube is completely solid aluminum. should be a good gasket between intake tube and motor. on carb side of intake there should be a gasket against intake tube. then the insulator, a thick washer fiberglass looking piece. then an o-ring between insulator and carb.

also check tightness of bolts. I have accidentally over tightened the bolts and then the vibration of the engine running actually stripped the hole.

let us know what you find

[ATC90JAY]

Hey guys, Here are some pics the gasket looks good or at least i think....I cleaned the whole carb and checked the float and everything seems fine. the carb is a new OEMSTD. There is only a o ring gasket between the carb and intake pipe? Is that normal? The Cable is super tight i have another one coming it almost seems too short.....Th going to pd ime gas line on the R inlet 183115183115183116was bent going to replace with clear line...What to try next?? Thanks, Im learning a lot!!

[trike savior]

that is your insulator on the cylinder head. not the right spot and is most likely causing the problem. move it to by the carb. set it up like I described in my last post and you should be good.

[ATC90JAY]

OK I will try that... thanks!! Let you know how it goes

[ATC90JAY]

Hi, I ordered a new gasket set, new point set I will get it this week!! I will let you know when I get it all together... thanks for your help!!!!!

[kb0nly]

I always replace the intake gaskets if i have to take it apart, they just don't seal more then once, once they have been tightened down and gone through a few heat cycles they harden and they won't re-seal if you remove it and put it back.

As already pointed out the insulator is on the head but should be between the carb and the intake, which is probably causing an air leak on both ends of the intake, on the head side because of the gasket and insulator combo and without the insulator between the carb and the intake the rubber o-ring won't have the correct surface to seal to.

Once you get gaskets on each end of the intake and move the insulator you should be ok leak wise.

[ATC90JAY]

Thanks KBonly I will seal it up and let you know if Im riding or still working~

[afdfirefighter]

183181183182183183183184183185
Thanks KBonly I will seal it up and let you know if Im riding or still working~

Hey I sent you a PM. If you need parts or have questions, feel free to contact me. Just picked all this up this weekend and have a couple 90s of my own.

[kb0nly]

183181183182183183183184183185

Hey I sent you a PM. If you need parts or have questions, feel free to contact me. Just picked all this up this weekend and have a couple 90s of my own.

Wow what a haul!!! Looks like a lot of good parts in there.

[afdfirefighter]

Yes I have everything off of these 90s from what I can tell so feel free to shoot me a message if you need parts.

[kb0nly]

Your going in my little parts book... Under ATC90 Hoarder... LOL!