Fixing the low idle on a 2006 Ducati Monster 620

[l0nest4r]

I am helping my niece with her 2006 Monster 620 and the idle speed is stuck around 800 RPM. This is way too low and the bike stalls all the time. I tried adjusting the air bypass screws on the throttle bodies but they barely change the engine speed at all. I have already checked the valves and the compression and both look good. The bike smells like it is running rich and it does not start as easily as it should. I even did a full sync with a meter and set the throttle position sensor to the standard 150 mv. Using the fast idle lever helps it stay at 1100 RPM where it runs fine but I want it to idle properly on its own. It seems like the mechanical settings are correct but the air screws just are not doing their job.

 

[bigbrain$]

@l0nest4r Have you cleaned out the tiny air passages in the throttle bodies with some carb cleaner?

 

[doremiiiiii]

I am helping my niece with her 2006 Monster 620 and the idle speed is stuck around 800 RPM. This is way too low and the bike stalls all the time. I tried adjusting the air bypass screws on the throttle bodies but they barely change the engine speed at all. I have already checked the valves and the compression and both look good. The bike smells like it is running rich and it does not start as easily as it should. I even did a full sync with a meter and set the throttle position sensor to the standard 150 mv. Using the fast idle lever helps it stay at 1100 RPM where it runs fine but I want it to idle properly on its own. It seems like the mechanical settings are correct but the air screws just are not doing their job.

You should check if the rubber intake boots have any small cracks that might cause an air leak

 

[thirstyThumb]

Are the spark plugs fouled since you mentioned the engine smells like it is running rich?

 

[l0nest4r]

I haven't cleaned out those tiny air passages and checked the rubber intake boots. But I will definitely do it now. Thanks!

 

[uglytruth]

Afaik, some riders find that a dirty air filter can throw off the idle vacuum on older Ducatis.