if its not the throttle...then what is it???

i was told it was the throttle but its not...as soon as i start it the damn thing revs up all the way, so if its not the throttle then what else could it be...i dont wanna leave it running cause its reving up so high and im afraid the engine might blow so i turn it off as soon as it does it....what could be the problem :?: :?: :?:

 

So the butterflys are moving back once you release the throttle?

I think it would be prudent to put the make and model of the bike on here so people can give you a good answer as to what to look at.

I'm pretty much just repeating what I've gleaned from looking at this site, but if i were you I'd pull the carbs off and do a thorough cleaning and get any gunk out of them, one or more of the diaphragms may have perforated or deteriorated as well, so check those with a torch so you know they are good.

I would definately wind back the idle screw somewhat as well. but the first place i'd start would be checking the butterfly valves and making sure they are barely open with no throttle.

 

http://xjbikes.com/Forums/viewtopic/t=1 ... clunk.html

should help you out some

 

alright thanks...by the way its an 82 xj 650

 

http://xjbikes.com/Forums/viewtopic/t=2 ... +carb.html

sounds like a similar problem here, might be some help as well.

I'd pull the carbs and give them a mighty good clean tho.

 

Disconnect the Throttle Cable.
Observe that the Carbs Throttle Cable Attachment Device is NOT jammed-up under the Cylinder Head.

Make sure the Linkages are not fouled by Intake Manifold Clamps.
>>Make sure the Intake Manifold Clamps are within the Groove for the Clamp and NOT on the Manifold.
>>If they were on the Manifold, ... Check for a "Clamp-edge Cut" through the Manifold.

Check that Rubber Diaphragms are mounted correctly.
Conduct Clunk Test.

Bench Sync Throttles using thinnest feeler medium possible.
(One-quarter Inch Wide Strip of 3X5 Card or Business Card.

 

check the choke circuit on the carbs, bet they are messed up

 

tire pressure

 

And this has what to do with a high idle?

 

I'd say that it's the idle adjustment screw. i've had a similar problem A while back. Now the only problem i have now is it constantly stalling when cold. I think my carbs are waaaaaay out of sync.

 

Did someone crank down your idle screw for you?

It will not run right until you do the sync IF that is the issue.

Don't forget to check the back flow modulator too.

 

quite often improperly jetted carbs (pilot circuit for this threads sake) wont maintain an idle, so to get an idle someone usually turns up the idle screw. when the idle screw is cheated in to get the bike to run, the throttle plates are essentially opened beyond the pilot circuit and into the main, and now the bike has a lot of air and fuel to play with while you are sitting at a red light, engine racing to infinity and beyond. as mentioned before, carb sync should be checked at least on the bench to get things started.

 

I'll bite, just what does that look like?

 

Whoa whoa whoa....slow down.

Did it just start doing this? Did you just get the bike? Is it just out of storage? What have you tried? What have you done with the throttle, if anything? Do you have a tech manual, owners manual, Haynes manual? Who told you it was the throttle? Did they say the throttle was the problem? Do you know on the carb which one the throttle is? (sorry, but you'd be surprised). How do you know it's "not the throttle"?

Welcome to the site. It is the best website in the internet, hands down.

You will find your answer here, but it helps to ask the right question.

Listen carefully to everything rick and robert say. Be careful with billb, though. He's a prankster. 8O