Idle problem !!!

[HarJim81]

I have a 1981 eleven special . The bike is in good shape . I try to make improvements on it every year . I recently had a guy replace the fork seals and the valve seals . It failed inspection because of the fork seals . I replaced the valve seals because it was smoking up on starting and fouling the plugs . Anyway , I got the bike back but the idling is screwed up . When you rev it up around 5000 it drops back to 4000 and stays there . I bring it down with the idle screw and then it stumbles and shuts off . I did it a few times . I replaced a couple cracked fuel lines . Nothing changed . I don't think he touched the carbs when he replaced the valve seals . Just pulled the tank off . I have cracking in my carb holders but I don't think it goes through. I am gonna replace them though . Any ideas ??

[TopCatGr58]

Hey there,

To replace the valve seals he would have had to remove the HEAD....USUALLY, unless he did it the more risky way of pressurizing the cylinders while compressing the valve springs to get the valve keepers and spring of to gain access to the seals that are beneath them.

SO...with the head off, if he also did some valve work...like at least lapping the valves to ensure that they are making good seals, then the flow dynamics of the head/engine have changed, and once the head is installed, and the carbs put back on, they would have required a vacuum syncing to get them to play together properly. Carbs out of sync is the most common reason for a hanging idle like you described.

But other things can catch the throttle plate, like the intake boot clamps so you want to make sure the throttle plate isn't catching on anything when you rotate the throttle.

T.C.

[2manybikes]

Idle problem

I doubt it's the intake boots. They can crack all over the place, and not crack all the way through. If it idled OK before you took it, something else has changed!

[Radioguylogs]

If you still don't find the cause...

You might ask the guy if he touched the carbs?

[HarJim81]

Thanks guys . Ill check and see exactly what the guy did . I'm gonna replace the carb holders anyway because I got a new set ordered . Maybe replace my fuel lines too . Then look it over for anything obvious . Then if no luck ill get them synced . Thanks again for the feedback.

[DiverRay]

To replace valve seals, he NEEDED to remove the carbs. You MUST re-sync them EVERY TIME they are removed. I would start there, after you R&R them for the carb holders.