1986 ATC 200x Idle Issues Help!

[jason0779]

Guys I'm reaching out for your opinions. My 200x has had idle issues since i bought it a while back. I rebuild the carb hoping that would fix it but haven't had much luck.

This is what its doing. The bike will idle smooth untill you start to rev the motor. When you rev the motor and release the throttle it will stay reved up for several seconds. If you take it for a ride it does it even worse. Ride it down the road squeeze the clutch and come to a stop and its screaming again. You can slip the clutch and the squeeze it back in and it will go back to normal idle. It has a 112 Main and 35 Slow Jet. The C-clip is on the second notch.

I noticed something strange about thrity mintues ago. I had the bike running and cut the fuel off and almost instantly the RPMs starting raising higher and higher and higher as if it was already out of fuel. Just seemed to quick. I'm going to pull the filter out and drop the C-clip and notch. Any other ideas/help would be great.

Thanks ahead of time!

-Jason

[honda200x1987]

I had that prob with my 87 X , if I remember right, I beleive you need to adjust the "Screw Set A" as seen in the micro finche number 5. It's the screw underneath the carb next to the bowl. Try that and if it doesn't help then adjust the c-clip on the needle to the 2nd notch from the pointed end of the needle or start from the bottom up till it's right. I am no expert but I rebuilt mine also and between these 2 adajustments it idles perrrfect!

[yaegerb]

I am going to say its either a vacuum leak or your slide is sticking in the carb throat. Start the bike and spray a mixture of soap and water around gasket areas (intake, carb, all hoses, etc.) Rev the bike and look for air bubbles.

[ZacH_GrifF]

My 185s is doing this too. I noticed that my throttle cable was moving in and out of the throttle assembly so I tightened it down with some zip ties and that helped a little. I also have a crack on each side of my intake boot behind the lugs sticking out where the studs mount. I put super glue in them to seal them up but haven't had the chance to crank it since I live in the city and we have a sound ordinance after 9 oclock. I also adjusted my cable adjustment on the top of my carb, it was all the way out holding the slide a little high, but it still is revving to the skies if i ride it.

[atc007]

Throttle cable/slide is sticking. You need to take off the air tube and watch your slide,verify it is snapping cleanly back to idle. If your cable is as new and all mechanically is working perfect. yes,I would say air leak. This is a fairly simple problem,just think it through,and you'll get it ! You want it to idle as high as it will on the air screw,then,adjust your idle back down on the idle screw.It is also Possible,,,rare on an 86,,but possible. Your carb is worn out like a 200s. They suck air around the venturi,and they're a paper weight.

[jason0779]

I've tried adjusting the pilot screw any where from lightly seated to 2 1/2 turns out. I've also tried moving the clip on all 5 grooves. Nothing has helped. Tried a different Carb with new jets and that didn't help at all. With all the different settings I've tried it all does the same thing. Barely idles with idle screw all the way in then when you Rev it up or try and ride it when you squeeze the clutch the rpms are screaming. Obviously when I put it on the 5th groove it was running super rich but still does the same thing. The Guy I bought it from said the Guy he bought it from raced it but I'm not sure he modded it. If he did bore the motor would a bigger small jet be a good idea to try. I too think vacuum leak I just can't find out where. Tank is clean removed filter too. Does same thing with gas cap off too. Getting very frustrating. My R never gave me this much trailprotrailprotrailprotrailpro when it came to tuning.

[atc007]

If you switched carbs and the problem still exists,it is an air leak for sure.

[yaegerb]

Jason....do what I recommended above. It will help you identify the leak.

[kb0nly]

Got a propane torch? Get it and don't light it, just turn it on really low til you can just smell the gas coming out, then put the tip of the unlit torch around the engine side of the carb and intake and where it bolts to the head, etc.. If engine speed changes when she starts snorting that propane you found a leak.

I just go done fighting this on a 125M, it would only self rev and hang rev on a cold days, and generally once the engine was hot it wouldn't do it anymore. Turned out to be gaskets on the intake. I just got a sheet of gasket material from my local NAPA and traced out a couple new gaskets and slapped it back together, purrs like a kitten now. But make sure you check the slide, i had one stick like that as well, and i have also had bad and sticky throttle cables so check it all out.

The rubber carb intake mounts sometimes crack and leak. I have wrapped them with lined splicing tape, aka self amalgamating rubber tape, i have also coated them with liquid electrical tape. Both of these are just a temp fix. New rubber intakes are easily available surprisingly.

[jason0779]

I will try the soap and water, and the propane trick. I know it is not the slide/cable as it is fairly new and very crisp/strong. Tried two different slides actually. I will be back over there to work on it tomorrow.

I noticed the intake between the motor and carb looks kind of shady. It twists alot when tightening the carb down. I took it off and noticed it has a the rubber piece in the center. It also apears to have a plastic like coating around the whole thing and is somewhat chipping and cracked on the motor side of this piece. This piece seems rather tuff to find.

I'm trying to eliminate as many things as I can. Does anyone thing valves or the auto decompression maybe be screwed up??? Just currious.

Thanks for all the input so far!

[jason0779]

UPDATE!!!
So I took the carb and intake off. Cleaned the carb again, cleaned the orings off around the intake and sprayed a little carb and choke cleaner down the intake then blew it out. Adjusted the valves, adjusted the auto-decompress cable, checked all the electrical. Oh and I put a different metering rod in the carb i'm using. It looked like the one that was in there was much wider??? Maybe because the carb had a 122 main jet when I got it and before I put a 112 back in it. So when I first starte the bike it was still running kind of crappy so I got it idling and checked for vacuum leaks with propane. Nothing.... Anyways after playing around with the carb, dropping the c-clip to the third notch and adusting the pilot screw a bit I got it running pretty darn good. Scooted around the neighborhood great, wasn't hang reving anymore and I could get up to 6th gear squeeze the clutch in and slow all the way to a stop while shifting down to first and it would idle perfect.

One last question ( for now) for anyone they may have some info. The bike is running good like I said but I have the c-clip on the third notch and the pilot screw is only about a 1/2 turn out. Does this seem strange????? I thought 1-1/2 -- 2 turns was pretty normal. Anyone??

Thanks again!