Ducati Monster Forum

Dear ducatistas,

I need your help! My Ducati Monster S2R 1000 is acting weird (I think). The idling hops back and forth. When turning on the bike, it is always perfectly fine, idling at around 1500RPM. When I start riding and stop however, it acts in one of three ways:

1.   Jumps in a rhythmic and steady manor from around 1000 to 1500 RPM, staying at each for about a second. It is not always 1000 to 1500, sometimes other values, higher or even lower, but always same difference, around 500RPM between the low and high value.
2.   It gets stuck at over 2000RPM with a steady idle, but still, super high value.
3.   Goes randomly back to normal at 1500RPM

One aspect worth mentioning is that if i twist the throttle ever so slightly and hold, then the two cylinders are running in sync.

I have changed all the spark plugs, checked the cables and now ask you what the next step is 😊

Background info:

Bought the bike a few months back, has been the same the whole time. I have done a few mods, but none that should affect the idling or engine behavior, nor has the idling changed at any point.
It has a ducati performance kit with full termis, performance ECU and performance airfilter with open airbox.
I have recently started purchasing cables to diagnose the bike using JPdiag, haven’t got that going yet though, and wanted to here your thoughts on this.

What are your tips for my next steps? 😊
Please, if you use any motorcycle related abbreviations write down what they stand for in parenthesis so I may learn the language ;) (I know none today)

Thanks all!!

I would start with checking for vacuum leaks.

Your bike has an Idle Air Valve (IAV) and I've seen a bit of that sort of behavior from bikes with IAVs.

A possible solution is to eliminate the airflow associated with the IAV.
I've only done that once, as it requires quite a bit of labor and it's not usually bad enough for folks to step up.

The IAV system airflow to *each* cylinder has to be blocked off, idle speed and sync re-set with the air bleeds.
Unfortunately that eliminates the cold-start idle control.

Brad Black did a blog post (maybe?) but I can't find it.

Thanks for the suggestion! Will start googling immediately :)

I had a similar symptom at cold start. It would bounce the idle around. I also had an stored code for Idle air valve malfunction. Setting the throttle body balance and trim helped some, but it still does in on colder morning startups. Getting the diag software setup is good, since it lets you recreate the issue by activating the valve. I think I will ditch mine if it gets any worse.

Thanks! I guess it’s time to bring the laptop to the garage then :)
There is no way I am ever selling this baby :)

To be clear, I meant ditch my idle air valve ;D, not the bike. I've thought about selling my Duc before, but then I go ride it, or spend a few minutes in the garage looking at it.

Regarding my idle issue, I might have solved it. I balanced my intakes again, and really nailed it this time. Much better idle over all. I also lowered my trim from 22 to 2. I had set it high after installing pod filters, since I didn't have an co meter, and I wanted to err on the rich/safe side. I think the over rich condition was causing it to almost stall, and the idle air valve was catching it, causing the bouncing idle. Idle is solid on cold start now, but the throttle is a little more snatchy at on-off transition. I might richen it back to smooth the throttle back out. I really need to get a gas tester to round out my tune up kit. Anyway, hope this helps and let me know how yours turns out.

Gunson gas tester is a useful and economical unit. Just warm it up well and calibrate it according the the instructions.