Ducati Monster Forum

Moto Board => Tech => Topic started by: Privateer on March 04, 2017, 03:11:01 PM

Title: 620 surging
Post by: Privateer on March 04, 2017, 03:11:01 PM
04 620, ~88k.  recent valve service.  ecu immob delete. 800SS dash.  stock airbox. slipons.

noticed yesterday when at constant throttle, ~40mph, lane sharing in the afternoon commute, engine surges intermittently.  I searched here and see a lot of posts about running lean.  I've also noticed i get an exhaust pop on engine braking, which I thought was a lean condition as well.

can't say that's happened before and nothing really mechanically is different so I'm a little perplexed.

any thoughts on the lean condition?

is there something I can adjust/change at home?
Title: Re: 620 surging
Post by: DarkMonster620 on March 04, 2017, 05:13:01 PM
Quote from: Privateer on March 04, 2017, 03:11:01 PM
04 620, ~88k.  recent valve service.  ecu immob delete. 800SS dash.  stock airbox. slipons.

noticed yesterday when at constant throttle, ~40mph, lane sharing in the afternoon commute, engine surges intermittently.  I searched here and see a lot of posts about running lean.  I've also noticed i get an exhaust pop on engine braking, which I thought was a lean condition as well.

can't say that's happened before and nothing really mechanically is different so I'm a little perplexed.

any thoughts on the lean condition?

is there something I can adjust/change at home?
if it's lean, you will need an electronic tool to set TRIM . . .

recheck ALL electrical connections and spark plugs . . .
Title: Re: 620 surging
Post by: Langanobob on March 05, 2017, 02:16:13 PM
What about a vacuum leak?  Might cause those symptoms too.
Title: Re: 620 surging
Post by: ducpainter on March 05, 2017, 03:02:01 PM
Never experienced an intermittent surge. They always seemed to be there...usually at constant throttle.

Could be vacuum, or a TPS, or perhaps not enough slack in the throttle cable.

It could be lots of things.

Why not have Nick take a look?

Title: Re: 620 surging
Post by: Privateer on March 10, 2017, 05:59:06 AM
Quote from: ducpainter on March 05, 2017, 03:02:01 PM
Why not have Nick take a look?



it's not easy for me to get to Nick, which is why I was hoping there was something I could adjust at home.
Title: Re: 620 surging
Post by: Howie on March 10, 2017, 06:35:10 AM
One thing you can DYI is look for an intermittent vacuum leak.  Spray suspect areas with, while moving suspect parts like the plastic intake tubes, well, carb cleaner works, but could damage paint.  A light oil spray might be better.  Any change in RPM means leak.
Title: Re: 620 surging
Post by: Gimpy on March 25, 2017, 10:11:09 PM
I have a 2001 m900ie, with the same condition.  Sorry for the noobness, but what exactly should I consider suspect?
Title: Re: 620 surging
Post by: Privateer on May 17, 2017, 04:54:35 PM
small update.

I swapped in some Cycleworks ignition coils and the bike seems to run better.  The surging at small throttle seems to have gone away.  I still get the decel popping, and what seems like a missfire once in a while, but the worst of it seems to have gone away with the new coils.

by the way, whoever decided on that airbox location for the h-cylinder coil deserves a special place in hell.
Title: Re: 620 surging
Post by: DarkMonster620 on May 17, 2017, 06:03:01 PM
Quote from: Privateer on May 17, 2017, 04:54:35 PM
small update.
~~~

by the way, whoever decided on that airbox location for the h-cylinder coil deserves a special place in hell.
[laugh] [laugh] [laugh]

Are you close to Speeddog? You might need to have your trim reset . . . Need electronic tool to do . . .
Title: Re: 620 surging
Post by: Privateer on May 18, 2017, 08:29:11 PM
i shouldn't have posted.  returned today.  in the 3500rpm area, at 30-40mph, get this stumbling/surging with a constant throttle.
Title: Re: 620 surging
Post by: Speeddog on May 18, 2017, 09:00:36 PM
I should have my magic electronics box back from repair soon, or have a similar unit in house.

Stay tuned.