Ducati Monster Forum

Moto Board => Tech => Topic started by: Jdan on September 11, 2011, 03:37:06 PM

Title: Sticking throttle
Post by: Jdan on September 11, 2011, 03:37:06 PM
I recently swapped the carbs on my 2000 m750 and ever since day one, I've had the throttle sticking open. The carbs were pulled from I believe a '98 900ss, but they were the same factory mikunis minus different jetting.

Once the engine gets warm and I start opening the throttle a decent amount it will stick open almost like my choke is staying open the whole time. I can get the revs to come back down slowly if I rev the engine really high, but then the throttle ssticks open again at the next light.

I've tried using throttle lube and even replaced the cables because I noticed a fray in one of the cables but the problem still stands. From my little experience I've realized that if the bike isn't running right, it's usually something wrong with the carbs.

Any ideas on this?
Title: Re: Sticking throttle
Post by: Howie on September 11, 2011, 08:55:59 PM
Assuming your throttles are sticking, remove the cables from the carbs and see if the throttles still stick.  Problem goes away, either cables, cable routing , throttle tube or something is contacting the grip.  Your throttles may not be sticking though.  If your idle speed is too high when the bike is hot you will be at the point where the ignition advances, raising your speed to about 3K RPM.  The cure is set idle speed to less than 1200 RPM (with a real tach, not the one on the bike.  Synch the throttles while you are at it.
Title: Re: Sticking throttle
Post by: Raux on September 11, 2011, 09:41:59 PM
Also lube your return springs
Title: Re: Sticking throttle
Post by: Jdan on September 12, 2011, 09:21:03 AM
The idle speed is already set at the correct rpms which leads me to believe that something is in fact sticking.

Quote from: Raux on September 11, 2011, 09:41:59 PM
Also lube your return springs

What and where are the return springs? I'll double check the cable routing this afternoon but i can still twist the throttle each way when the rpms go up.
Title: Re: Sticking throttle
Post by: corey on September 12, 2011, 02:06:59 PM
my throttle sticks all the time too...
[evil]
Title: Re: Sticking throttle
Post by: greenmonster on September 12, 2011, 05:22:43 PM
+1 on cable routing.

Air leak carbs-rubbers-manifold-head.
Too lean at idle.
Missing Oring under black top of carbs.
All jets from 750 carbs moved over, incl air jets in carb mouth?
Title: Re: Sticking throttle
Post by: koko64 on September 12, 2011, 09:00:12 PM
+1
Those things can cause a hanging idle. If nothing is sticking mechanically, then the idle could be hanging up for any of those reasons.