Running Rich...my Monster that is.

[Monster Dave]

Hey guys,

So recently, I've been noticing that my monster's exhaust is smelling a bit more "rich" than usual. I have 22k miles on my '03 620. Is this simply a sign of being due for a tune-up?

On a side note, although she's fuel injected, when I start her up from a night of sitting, my bike idles a bit rough (up and down) and requires some throttle input initially to keep it from stalling. After it's idled for 10 sec or so it doesn't need any assisitance; though it still idles up and down a little.

Any suggestions?

[fastwin]

My '07 S2R1000 did something similar and I have heard of several other DS1000 motors doing the same thing. Idle up and down, stalling, etc. Mine was solved at the 600 service with a Termi pipe install, open air box lid and groovy new ECU. Wasn't exactly the cheapest fix. But all that stuff was going to be installed anyway fussy engine habits or not. I know your bike is different but the issues sound similar. I'm sure you will get much better answers from others on the board. When is the next service? 24K right?

[Monster Dave]

Yeah, 24k is the next service.

I've been dreaming of a set of Leo Vince CF lowmount pipes for over a year, but I don't think that they will make as much difference as your upgrades did!

[clubhousemotorsports]

A tune might fix it if they find something off in the fuel injection set-up.

If either the ECU or a sensor is failing the bike will run  rich as well. your bike is prone to both.

First I would look at the cylinder head temp sensor (on the horizontal intake valve cover), unplug the sensor and see if the connectors are corroded. If they are green you may be able to clean them up and the bike will lean out, if the connection is corroded the bike will run rich.

[mxwinky]

Very doubtful that the fuel injection is out of tune to the point of being that rich, especially since these bikes (stock) are setup on the lean side for emissions compliance.  Additionally, the DP ECU for the Termis richens the mixture further, which will only exacerbate the rich running you're already experiencing.  Far more likely is that you've got some loose valve guides that are passing oil into the combustion chambers.  Your bike has a fair amount of miles, but Ducati has been very good about covering this problem since it's emissions related and they want their bikes to remain emissions legal.  If Ducati won't cover it then make sure your dealer uses better guides than stock (such as the MBP guides) so you won't have a recurrence of this problem in the future.

[Howie]

Very doubtful that the fuel injection is out of tune to the point of being that rich, especially since these bikes (stock) are setup on the lean side for emissions compliance.  Additionally, the DP ECU for the Termis richens the mixture further, which will only exacerbate the rich running you're already experiencing.  Far more likely is that you've got some loose valve guides that are passing oil into the combustion chambers.  Your bike has a fair amount of miles, but Ducati has been very good about covering this problem since it's emissions related and they want their bikes to remain emissions legal.  If Ducati won't cover it then make sure your dealer uses better guides than stock (such as the MBP guides) so you won't have a recurrence of this problem in the future.

The scenario ducvet described will make the bike run extremely rich since the computer will think the engine is always cold.  That sensor connection is also a lot easier to check than valve guides

[clubhousemotorsports]

Yeah thats what I meant.  lol

An overly rich bike is a good symptom of a EFI component that is failing. Mxwinky is correct that the bike should not be rich in stock trim, we are talking about an abnormal condition.

I just did a tune on a bike that had the ECU change its trim value all on its own while running on my lift, In this case it went full lean -125. I have seen it happen in both directions.

[mxwinky]

Granted on both counts.  What would be nice to know is whether this rich running condition has been gradually getting worse or if it came on suddenly.  If it came on suddenly then the sensor would be the most likely cause.  At the mileage indicated, the guides are a strong possibility however and are actually very easy to check.  Pop one of the covers off the horizontal head and you should have enough easy access to wiggle the valves and check for obvious or excessive looseness.  When they're bad they're pretty sloppy and easy to feel.