i have owned my 750ss  along time , but the carbs have always been a little of beat and rear cylinder is hesitant at idle , My other ducatis dont do that ..


The  Mikuni BDST 38s run great above 2k rpm all the way to over 125mph++ but are lumpy a at tickover and rear cylinder is hesitant at tickover until 1500 rpm then its fine all the way to 8k rpm . and always have been for last 20 years but its annoying me , so i have the carbs apart again , they were ultrasonic cleaned twice last year and i rebuilt them with new parts , gaskets ,orings , new emulsion tubes ,new diaphragms , new bypass rubbers ,, etc etc but it made no difference ,, only parts i did not change 5C19 was needles,,, and slow running jets , float height 14mm ,, this is bugging me for many years LOL
 
140 main jets,
70 pilot jet 
1.4 slow jet   
5C19 needles new emulsion tubes
13mm Float height
New airscrews  and Orings etc etc

NO AIR leaks , Engine Valves are perfect etc etc
electrics are also all new plugs , Ht leads, coils pickups etc etc ,,

bike runs lovely but once off idle ,,, I want it perfect like my Monster 750 only difference is M750 has stage 2 Dyno jet ....

+1.

I`m wondrin how a snapped belt could damage a plug like here?
Usually only causes piston and valve to meet or?

Have a good look at the idling system. Idle synch is reported to reset with three runs of cycling ignition on/off.
Idle stepper system can get dirty and cause problems. Access the area via tank removal and clean those components.
Check the condition of the idle breather hose to the airbox.
Oh, and do all the other stuff suggested.

Quote from: Howie on March 31, 2026, 07:04:58 PMThe tube ain't too bad, it's the prep.

I wasn't referring to a butt cam, if that's what you're referring to. That's a whole lot of nothing other than the prep, as you say.

There are other orifices that the medicos like to probe that are far less make the beast with two backsing pleasant.

The tube ain't too bad, it's the prep.

Or you could use the shogun method if you like wasted work and money.  Check for vacuum leaks. then adjust idle speed, set CO and synch.  Still no good, most likely the idle speed motor

I'm not surprised at all.  I went to a dealer and he asked me to put at least 40 miles on the bike.  I mabe did 15.  Great, much better bike than the 750.  I was thrilled to be back and stretched out on my Monster.  I also liked  the 750 more than the 1000.

Welcome!

Quote from: Kopfjäger on March 31, 2026, 08:40:55 AM

That was pretty friggin awesome.

The floutist for Canned Heat didn't have a lot of respect for the "Lip Synching" bullshit. Classic.

I agree your high idle issue isn't from the typical causes, ie a vacuum leak.

Low voltage can wreak havoc on electronics. It's possible the ecu was damaged, the software corrupted, or a sensor failed.

If you don't have some sort of diagnostic equipment you're going to need to get it to someone that does.

Hi all,

I know there are many posts regarding high idle speeds but I haven't been able to find anything that matches my situation.
I have a 2013 Monster 1100 Evo with about 16000 kms on the clock. I replaced the original battery with a LiFePo battery about two years ago which worked fine until I left the bike un-ridden for a couple of months without a trickle charger. I charged the battery using a Victron charger (set to Li mode) and it started and ran with no problems. After a short ride and a few minutes with the bike turned off, I tried to start it and the battery was pretty much dead - the engine would basically turn a single revolution and not start. I couldn't bump start it due to the high compression and the location (no hills & no-one to push) so I persisted cranking and, after a half-dozen or so attempts, surprisingly it started. The problem was that the idle went straight to about 3000 rpm and stayed there. I suspected some sort of ECU issue due to the state of the battery and the multiple start attempts. I rode it home and did some Googling and the only suggestion I could find was to turn the ignition on, wait until the instruments go through their initialisation sequence, turn it off without attempting to start the bike and repeat this process several times (presumably to 'reset' the ECU). I did this, along with replacing the Li battery with an OEM-equivalent sealed lead acid battery, but the problem remains. When I start the bike it immediately idles at 3000+ rpm.
I know there are many potential causes of a high idle speed but the fact that it had been perfect until the battery/starting issue and then immediately went and stayed super high seems to suggest some sort of ECU or other electrical issue.
Any ideas? Any help would be greatly appreciated. Thanks.