Throttle Stuck Wide Open

[250-R-250]

Great,

I don't even do anything to it and it breaks. THE THROTTLE ON MY QUAD IS STUCK ON FULL OPEN. Its weird, I will attach some pictures. I have not ridden this thing in a long time. It is a YAMAHA Beartracker Utility. I figure carbs have the same princable so maybe someone knows whats going on. Its odd, because I have little tension on the thumb throttle. But the spring is still entact, and also at the part where the trottle is on the carb. I can press the trottle and see the lever going up and down. I think this means that the problem is inside the carb, what could this be? This makes me angry. Even though I have not touched it in awhile. How does something like this break.

Here is the inside of the Thumb throttle while I hold it full open.http://usera.imagecave.com/Kane/DSCF1686.JPG
Here is the Inside of where the cable attaches on the Carb. You can tell the cable is still attached and moving the lever. Right here I am holding it full open. http://usera.imagecave.com/Kane/DSCF1687.JPG
Here I am not even touching the thumb throttle. I guess this should be at the idle position.http://usera.imagecave.com/Kane/DSCF1688.JPG
In this picture, I moved the lever down even more. Not sure whether it should have that much slack in it. But you can tell that I can push the lever down past my weak idle position.http://usera.imagecave.com/Kane/DSCF1689.JPG

[NacsMXer]

Looks pretty rusty and dirty inside that carb housing....it really shouldn't be so. Moisture should not be getting in there at all. Did the cover have a gasket on it? I would do a full dissassembly/cleaning/lube of the carburetor throttle linkage or replace the carb altogether. I would also lube the throttle cable with silicone spray or replace it with a new one. If you don't know how to do this then get a service manual for the quad if you already don't have one. Sorry I can't be more specific as I don't have experience with that quad :ermm:

[nicktrx400ex]

i agree with^ take it completely apart and clean everything that can be touched

[250-R-250]

I would,

but I do not know how.

I just want to figure out why it is stuck wide open.

[nicktrx400ex]

clean it just get like a wire brush to rmove some of the thick stuff and spray wd40 on the little thing the cable conects to on the carb

[Toadz400]

Originally posted by 250-R-250
I would,

but I do not know how.

I just want to figure out why it is stuck wide open.

What don't you know how to do? It's very easy to take the carb out and clean it. I believe this is the only proper way you can find out why the throttle is being stuck wide open.

Btw, I would think a Nuclear Engineer could figure it out;) . Find a manual for it and it'll tell you exactly what to do. Just make sure to get some carb cleaner as it looks like you're going to be using a lot of it.

[idontknowwhoiam]

could be a kinked throttle cable...i know iv had that happen to me when i crashed dirtbikes b4....never done it on a quad though

[wilkin250r]

I'm just going to reiterate what everybody else has said.

That carb is garbage. You want an easy solution, and there just isn't one. That carb needs to be taken off and cleaned. You want to know the reason your throttle is stuck open? It's because the carburetor is full of junk, and needs to be cleaned.

If I were you, I wouldn't take shortcuts. You get a stuck throttle in a tight squeeze, and you could wind up in the hospital. Even if you manage to jump off and save yourself, your quad isn't going to survive, and you'll end up with a hefty repair bill. Sure, you think you'll just hit the kill switch, but I bet my paycheck that you don't get to it in an emergency situation. You're headed for serious problems, all because you want to take the easy way out.

[250-R-250]

Alright Wilkin,

You are the man, So I guess I will start on this tommarrow afternoon. I am sure that I will need help with this. I can get a clean used carb off of ebay for 40 so that may be the best way to do it. Either way, its coming off, I knew I would have to do it......Ill post back tommarrow if I find anything. Yes, the carb is junk, it just doest run right either. The thing was submerged one to many times, we had a guy rebuild it and he did a ****ty job.....

[Toadz400]

Originally posted by 250-R-250
Alright Wilkin,

You are the man, So I guess I will start on this tommarrow afternoon. I am sure that I will need help with this. I can get a clean used carb off of ebay for 40 so that may be the best way to do it. Either way, its coming off, I knew I would have to do it......Ill post back tommarrow if I find anything. Yes, the carb is junk, it just doest run right either. The thing was submerged one to many times, we had a guy rebuild it and he did a ****ty job.....

Why do we need Wilkin in a thread for anyone to take us seriously? Haha, no offense to you Wilkin as you really are "The Man".:cool:

[wilkin250r]

Originally posted by Toadz400
Why do we need Wilkin in a thread for anyone to take us seriously?

I'm not the only knowledgable person on the site. You guys all gave the same advice. But that's ALL you did, was give advice. You told him WHAT to do, you never said anything about the reasons WHY, you never explained the risks involved with taking the shortcut. A stuck throttle can spell disaster.

[250-R-250]

^ Word


Anyways, I am getting around to raking the carb off today.

I shut the fuel valve off after it starting pouring out all over me:rolleyes: Then I disconnected the boot and all that. But to pull the carb out I have to take the throttle cable off. Now how do I do this? I dont see a place to do it in the pictures I took earlier in this thread. Any ideas?

[250-R-250]

Oh,

and is it possible that this is an air leak? Or would that not cause it to constantly be in Full throttle

[250-R-250]

Here is a picture of where the cable goes into the carb. That looks like a place I could put a wrench or turn. But will that just tight or loosen the cable? Or completely take it off?http://usera.imagecave.com/Kane/DSCF1714.JPG

[NacsMXer]

You need to take that black plastic cover off that says "Mikuni" on it. Remove the phillips head screws, take the cover off, and you should be able to see the throttle cable wrapped around a pulley mechanism. Manually turn the cable pulley with one hand and unhook the throttle cable with the other. There may be another jam nut on the top of the throttle cable where it enters the carb, just look at it and determine what needs to be taken off to get the cable out.

That long piece where it looks like you can put a wrench is for cable adjustment btw.

[250-R-250]

brb thanks

[250-R-250]

Ok, got the cable loose from the lever. I got the carb where I could look down the intake. When I move the throttle lever, I can see the flap inside moving up and down. This means that it should be responding when I press the throttle on the lever, this also means the throttle should be operating. What else could it be?

[wilkin250r]

Just because it's moving now doesn't mean it doesn't have a problem.

There are many places for a carb to stick open. It could be in the cable, it could be in the pulley mechanism that the cable attaches to inside the carb, or it could be the slide itself.

It might not be sticking right at this moment, but if you haven't found and corrected the problem, it could return. My advice is still the same, you should take the carb all the way off, take it apart, and clean everything out. When you reassemble it, make sure everything moves freely and smoothly, including the cable. My first suggestion would be a new cable, but if you honestly can't do that, then certainly lube up your existing cable. (A cable luber is usually half the price of a new cable).

And, to answer your previous question, no, and air leak would not cause it to run like the throttle was stuck open.