Throttle Problem

[smiley88]

I've got a '02 CR250 (2-stroke) and on two seperate occasions the throttle stuck wide open. The first time I thought it might be a one time problem however since it's happened twice I'm afraid it might happen again...at a more inopportune time!! Other than the throttle cable actually sticking, is there anything else it might be? The reason I ask if it could be anything else is because I don't remember there being any slack on my throttle. I could be wrong though, it all happened pretty quick.

 

[sumx54]

Check the spring on top of the slide in your carb. It might be binding up or broken. Check the cable for any fraying. You can replace all the parts for about $45. Thats pretty cheap compared to a major injury or worse, someone else's injury. Lube all cables at least 4 times a season and look for any pinch points where the cable might be getting pulled...Good Luck.

 

[dooryder]

Ive had that happen many times, and i find its usaly just dirt or sumthing making my throttle tube think, just my 2 cents

 

[chadwik74]

Check the length of your bars. I had a 01 and every time I would turn sharp, it would pull the cable tight. Kinda scary until I figured it out. I just took a pipe cutter and trimmed off about 1/2" on each side. Now I do it on all the bars for the comfort value. JMO.

 

[smiley88]

I'll replace the cable and check the spring in the carb. Thanks for your help!!

 

[TABSTER]

I knew a guy once that very same throttle thing........... I think it was his purse strap................. HAHahahaaha

Keep use posted as to what you find.... You seem to have lots of good advice already..

 

[dirt biker nate]

I would check the umm i know the part not the name the part on the throtle in the carb, once i got it wet and it sesied.

 

[Waxy]

This is NOT the time to get lazy. :d

Take the carb off the bike and thoroughly clean it.

It can only be one of a few things -

Cable routing - make sure it's routed properly from the bars back

Cable itself - take it off and check it out, it should move very easily, if not, replace it, they aren't all that expensive

Spring mechanism in the carb - check to make sure it's in properly and not binding

Carb slide - take the carb apart and pull the slide out of the carb body. Often times the metal coating on the carb slide can start to deteriorate and peel off, not only will this potentially cause the carb to jam wide open, but those flakes of metal are going through your engine.

Needle - it's a long shot, but make sure it isn't bent or scratched/notched

I'm assuming it's a standard Mikuni PWK carb, so just get the model number and Google it. There's tons of info out there on the net on how to go about this, including full schematics.

Waxy

 

[poppajon]

don't forget to take apart the throtle tube and cable slide/guide assembly. A little grit/crap in there can make for an interesting hill climb!

 

[glengine]

I've had it happen to me on a few occasions.. Is the end of your grip torn? Lots of times it is either the cable itself or dirt between the bars and the throttle tube.. It could also be something in the Mechanism part where your cable hooks to the throttle tube.. Sumx54 made a really good point, you always lube all cables a few times a yaer.. That goes for dirt and snow stuff.. Did you change anything on the bike before this problem happened?ie grips bars anything like that.