Ducati Monster Forum

Moto Board => Tech => Topic started by: greenohawk69 on February 14, 2017, 06:36:10 PM

Title: 97 M900 - rough running
Post by: greenohawk69 on February 14, 2017, 06:36:10 PM
I did not start my bike since July 2016 and in the meantime, and recently performed the following:

* removed vacuum petcock
* removed vacuum line from intake manifold
* plugged / capped vacuum hole on intake manifold
* installed 5/16" fuel line

Bike started with the choke and would run, but once I dialed back the choke eventually to off, it would run slower and then stop.

After I started it again and pushed the choke off and used the throttle to keep it running. At low throttle, it started to cough a bit out of the open airbox (new K&N filter). Goosing the throttle a bit more, it revved higher and did kick out a little plume of black exhaust.

This was done in the driveway and not riding the bike due to slight weeping of tank drain plug.

Prior to the above changes, it would start with the choke, run and then rev higher and I would turn down the choke and then off after it warmed up.

Suggestions?
Title: Re:
Post by: greenohawk69 on February 14, 2017, 06:59:34 PM
When I re-installed the exhaust, I did install new gaskets into each port - there were none when I removed the exhaust this summer.
Title: Re: 97 M900 - rough running
Post by: koko64 on February 14, 2017, 07:21:34 PM
Not starting since last July is the key. There is every chance your carbs need a clean and service including unclogging the pilot jets and cleaning the float needles and float valves. Quite common with modern fuels waxing up or jelling over time. I would run fuel stabilizer when storing fuel in your bike. There are threads about how northern hemispherians can winterize their bikes. Even down here where we seldom see 30 F I start my bike weekly and run it hot. We ride all year around and seldom need to winterize our bikes. A big issue up your way and carbed bikes suffer most.
Title: Re:
Post by: greenohawk69 on February 14, 2017, 07:36:10 PM
It was stored in my garage prior to that for over a year and it started and ran fine. This time, I did store it with Stabil Marine and had run it through. Tank was empty from July until 3 days ago.  Thought I might have a potential problem with the carb. 

I'm from a cold weather state.  ;
Title: Re: 97 M900 - rough running
Post by: koko64 on February 14, 2017, 07:58:55 PM
Flooding carbs can give similar symptoms. What do the plugs say. Goop can also cause flooding when it gets under the float needles.
Title: Re: 97 M900 - rough running
Post by: ducpainter on February 15, 2017, 03:48:56 AM
It does sound like the pilot jets are munged up.

If you think it would work, I'd try putting a few miles on it while running the choke to keep it from stalling. It might come out of it.

I wouldn't be looking at plugs quite yet.
Title: Re: 97 M900 - rough running
Post by: Howie on February 15, 2017, 04:42:51 AM
Fresh gasoline and filter too.  You can burn the old crap in a car.
Title: Re: 97 M900 - rough running
Post by: ducpainter on February 15, 2017, 04:45:20 AM
I also wouldn't hesitate to put a little Techron in the fresh fuel. It won't hurt, and it might just clean things up.
Title: Re:
Post by: greenohawk69 on February 15, 2017, 07:09:32 AM
Fresh gas is in the tank. I'll try the Techron also. I'll run it some more too. Thanks.
Title: Re: 97 M900 - rough running
Post by: ducpainter on February 15, 2017, 07:33:11 AM
Let us know how you make out.
Title: Re: 97 M900 - rough running
Post by: greenohawk69 on February 15, 2017, 02:56:55 PM
Ran it for about 15 minutes. Started fine with choke and dialed back and then idle was low and then engine stopped. Started again with no choke and held throttle to keep it running. Revved it a bit higher and heard some popping out of the exhaust. Attached pictures of exhaust - changed in color is after I sanded it to a shinier silver. (https://uploads.tapatalk-cdn.com/20170215/dd874d627e106b75b53473c6ac1897d5.jpg)(https://uploads.tapatalk-cdn.com/20170215/de5d578b03dc3fac6a16c8174dcb14e0.jpg)
Title: Re: 97 M900 - rough running
Post by: ducpainter on February 15, 2017, 03:17:59 PM
Not sure what you're trying to show with the pics...but...

I don't think 15 minutes is going to do much.

If you can get it to ride reasonably well using the choke...put a tank full through it.

I understand the better living through chemistry thing, but it isn't instantaneous.
Title: Re: 97 M900 - rough running
Post by: Howie on February 15, 2017, 03:23:23 PM
Or just clean the carbs.
Title: Re: 97 M900 - rough running
Post by: ducpainter on February 15, 2017, 03:29:06 PM
That's always an option. ;D

We don't know his motivation level...or his climatological challenges.

Whatever works. [thumbsup]
Title: Re:
Post by: greenohawk69 on February 15, 2017, 03:37:57 PM
Motivation is fine. Lol  Drain plug has a slight weep that I need to fix with sealant I just got. The pics of the exhaust were to show color changes and if it someone was able to see if a definite rich or lean condition.
Title: Re: 97 M900 - rough running
Post by: ducpainter on February 15, 2017, 03:42:02 PM
I don't see enough of a difference in the exhaust pics to come to any conclusions.

Like howie said...you can pull the carbs apart and clean them, or use my lazy ass method, and try to ride it out.
Title: Re:
Post by: greenohawk69 on February 15, 2017, 03:43:59 PM
The front / vertical cylinder part of the exhaust was a shiny silver. I'll probably try to ride it out first as I have some time in the next two days.
Title: Re:
Post by: ducpainter on February 15, 2017, 04:08:16 PM
Quote from: greenohawk69 on February 15, 2017, 03:43:59 PM
The front / vertical cylinder part of the exhaust was a shiny silver. I'll probably try to ride it out first as I have some time in the next two days.
If you mean the front/horizontal cylinder...OK, but the two pics you posted only look like two different aspect ratios of the same pic on my 'puter.

Is it running on one?
Title: Re:
Post by: greenohawk69 on February 15, 2017, 04:11:26 PM
They are two different aspects of the same shot - was trying to show the shiny silver vs. the darker front. It feels like it is running on both. I'll lnow more in the next two days or so.