[Kmaz101]

Hey,

I am having problems with a sticky throttle, recently i had the carb off the bike and gave it all a good clean, but now that it is back togeather and in the bike the throttle sticks open. the carb is fresh and the throttle tube is all cleaned up, i also cleaned and lubed the cables so i have no clue what else it might be?? any ideas?

[Leardriver]

The throttle cable are easily pinched between the inside of the frame and the gas tank when you reassemble them.

[Kmaz101]

the tank isn't even back on yet, there isn't any place it could be pinched so i have no idea why it is sticking.

[JimDirt]

Its the cable setting at the carb , when you attach the cables , you have to adjust the slack at the carb with the locknut , you need to keep loosening the one with the locknut and working the throttle till it snaps back , if you go too far it will also not snap back , so its not totally loose , but its not all the way tight either , the other cable goes all the way tight , the one with the nut is the one that causes the throttle to stick

[Kmaz101]

so when you say loosen it you mean turn it out, like to the left? (i know lefty loose righty tighty) but i just thought turning it in to the right would give the cable more slack which would help it snap back, ill try that tomorrow! i really don't want to take it all back apart.

Now that I've got you here do you know much about a stainless steel valve swap? I've got some problems with shims that i have a question about.

[JimDirt]

Ask away on the valves , and it does not matter if they are Stainless or Titanium , they shim the same

For the carb , all you have to do is have the seat and tank off , then look at the cables where they go into the carb , one has a locknut , adjust that one in and out by hand till the throttle snaps back,then adjust and set the locknut to that position , then try again to make sure its still free (turning the bars completely locked left then to right testing each way) , if still free , then put the tank and seat on , and go riding !!

[Kmaz101]

I've got the throttle fixed, thanks for the help on that! better than ever before.

now for the valves, i just put new ones in. my last shims were at 1.8mm and 1.2mm, now after new springs and valves etc etc it reads that i need a 1.9 and 1.5mm shims. shouldn't i need bigger shims than that with brand new valves? I'm worried i will run out of shim adjustmet with shims that are that small.

[JimDirt]

Did what i suggested with the cable fix the issue or did you find something else wrong ??

As for the valve shims
It depends on how the seats were cut , if they cut deep to rid any major issues , then the shim would be smaller , when the seats are worn down enough they need replacing , when its replaced (hopefully by someone that knows what they are doing) , then they can get the surface up higher where its supposed to be , which will give you the ability to use a larger shim

The deeper the seat is cut the closer the valve stem is to the bucket , so the shim becomes smaller (same way when the valve itself gets worn , the gap becomes smaller to the bucket , the ONLY way to remedy this is to replace the seats to , so to speak , "Start From Fresh" , or to replace the head with a new one (you can get bare heads or complete with valves/springs)

PM Ken (link below) the owner of this site , since he does this work daily in his shop , he can give you a more detailed answer and suggest what needs to be done to "correctly" remedy it (most likely by replacing seats on the next valve job)

http://www.crfsonly.com/forum/profile.p ... rofile&u=3

[Kmaz101]

what you suggested for the throttle fixed it, it would get stuck wide open and now it shuts on its own, not an immediate snap but very very good.

as for the valves, in this case now that its back together i should just shim it and check it as normal until they need to be changed again? steel valves usually don't move very much anyway so i should be good to go correct? hopefully ill have a new bike before these need to be done again anyway.

[JimDirt]

Glad to hear , you can also mess with the adjuster where the throttle cables go into the throttle housing (on the bars) , you might get more "snap" , you want it as free as possible to avoid a stuck throttle , stuck throttles usually do not turn out good for the rider

Not that its the "norm" , but my Stainless intakes have been in my 06 450X since 06 , i have not had to adjust them yet , if that says anything , i also just put them in my 02 450R last winter , so far , no movement and i have raced it once (5 moto's over a weekend , plus practice for 3 days) and trail and track riding every weekend for the year

But like i mentioned , talk to Ken , and see what he thinks , he can tell you more than i can about what to expect and weather you should worry or not

[Kmaz101]

right on, thanks a lot!

[therooster70]

Hi,
I put on a set of fully framed bark busters and ran into a bit of binding where the bolt went through the throttle tube into the bar end. When I would really torque down the bar end expansion bolt it would drag against the hole in the tube. I just enlarged the whole a touch in the tube and that fixed the issue. Snaps back nicely now.