2000 R1150GS Sputtering at mid RPM's

[PARATOAD]

I have a 2000 R1150GS with 73K miles. Had a clean bill of health after the 70K mile maint. Ran great all winter, but recently has started Sputtering at mid RPM's when given a steady throttle input and it seems to be getting worse. I notice it mostly at slower speeds in 1st or 2nd gear. If I roll on the throttle it seems to stop sputtering. It seems to be a fuel issue, but I'm unsure. I travel with work and sometimes may have a tank of fuel for 2 months. Do you think it could be fuel that has broken down/gumming up and is there a worthwhile additive that I can try before moving on to more costly efforts? What do you guys think?? Anyone had a similar issue? What was it and how did you fix it? Thanks!

[vagueout]

Suggest starting with the simple things first, in this case i would add some injector cleaner into the tank, some fresh fuel, ride and see if any improvement.

[loukyairhead]

This problem should be easily remedied with a generous application of Liquid Nails and sound whacking with a hammer. If this does not work, try a larger hammer.

[PARATOAD]

Thanks for the insight. I ran the Fuel Injector cleaner through and put some sea foam in the next tank so I am replacing the spark plugs tomorrow, and if that doesn't fix the issue then I am leaning toward the coils. What are your thoughts?? I don't have any experience changing out coils... I am thinking about giving it a shot...Anyone have any lessons learned or advice on things to watch out for?? It bums me out when the bike is down...I really do love that machine.

[pgods]

Sorry, I don't know anything about the 1150, but "sputtering" and engine hesitation under load for my 1200GS meant a new fuel pump electronic.

[def]

The ignition system on your model uses a single coil that fires both plugs simultaneously. This is called a wasted spark design. Your ignition coil can be checked with a VOM. The readings should be as follows;

Primary= ~.5 Ohms
Secondary= ~7.5 Kohms (cold).

If the coil is good, then I would suspect the ignition wires to the plugs. They can be checked at night in a dark garage with the engine running. Look for arc over or corona especially at bends or where the wires contact any metal.

If the wires are good, I would suspect a fueling issue. Possibly the fuel line(s) inside your tank are cracked and are not supplying adequate fuel pressure when you apply throttle. Remove the fuel pump plate and inspect the fuel lines and other apparatus inside the tank. Change the fuel filter while your in there. Report back your findings.

[roger 04 rt]

The suggestions so far seem like good ideas, especially DEF's. I recently had leaking hoses in my fuel tank (that eventually brought me to a stop). The symptoms were more noticeable at higher power levels (WOT, RPM above 3,500).

If the other ideas don't bear fruit, the O2 sensor might be leading to leanness at mid-RPMs. One thing you could do on a cool day is see how the bike runs before the O2 sensor kicks in. Using my GS-911 I've found that in the summer you only get about two minutes from the time you first start the engine.

So what I'd try, first thing on a cooler morning. Start your bike and immediately get to the rpm and gear range where you have the problem. See if the stumbling is different before you get to 1 or 2 bars on the RID. Before 1 bar, your bike is in Open Loop (meaning not using the O2 sensor) and the Motronic is adding a few percent to the fuel.

There are also some "fuel trims" or Adaptive Values that get built up over time. You can erase them by pulling Fuse 5 for a minute or two. If you do this don't forget to relearn the throttle positions (after reset, turn key on, throttle to full and back twice with Cold Lever off, key off, restart). Then try a ride from Cold to a few bars and see how the problem area responds. You could also unplug the O2 sensor after resetting and see how it runs.

All in all, it's pretty hard to diagnose the O2 sensor without a GS-911 or some other special instrument but if it has worn out it can lead to poor running.
RB

[tagesk]

Either remove the side cover of the tank, or the filler cap, so that you can look inside.
Make sure the paint has not started to peel off; has been reported here more than once!

If the pain peels, it can and will quickly clog your fuel filter, and lead to all sorts performance of issues.

[TaSK]

[vintagerider]

All good suggestions. I always start with fuel prep/delivery system full maintenance. Noted that your problems are after storage. TPS could have a dead spot. Last of the things mentioned that I would check.

[PARATOAD]

OK Fellas, you have all had some great suggestions. I have replaced and gapped the plugs, but the problem still exists. One thing I did notice was that when I first started the bike and let it warm up for 30 seconds, the sputtering "seemed" to have stopped. I rode it for a few minutes and it returned. That sounds similar to the condition you described Roger. Keep the ideas coming... I'll keep you all posted. Thannks again!!

Mitch

[KShow]

this probably is not it, but check your throttle pulleys for debris. Had a small stone wedged in one of mine and caused some weird behavior.

[roger 04 rt]

Originally Posted by PARATOAD

OK Fellas, you have all had some great suggestions. I have replaced and gapped the plugs, but the problem still exists. One thing I did notice was that when I first started the bike and let it warm up for 30 seconds, the sputtering "seemed" to have stopped. I rode it for a few minutes and it returned. That sounds similar to the condition you described Roger. Keep the ideas coming... I'll keep you all posted. Thannks again!!

Mitch

A key question is, was it smooth before you hit 1 bar or 2 bars on the temp display? To make this test you have to ride it off immediately, no warm up and get to the test condition while the engine is cold (1 bar or less). You'll have to let it sit for several hours to get back to cold. The is a much better diagnostic test in the winter because you get more cold enrichment and more time--almost 5 minutes.

Also, I would run two tanks through with Techron concentrate added. It's a good cleaner. Run out the old fuel first though.

[slashbike]

My '02 1150GS with 71k was doing just that. I gave it a full service to establish a baseline, changing the fuel filter, air filter, and spark plugs in the process. Changed the O2 sensor, as it was burnt out as well. Nothing changed the stutter problem.
Then I changed the spark plug wires...and the bike ran like new.

[PARATOAD]

Roger, I completely get what you're saying. As luck would have it, I was "kitted up" and ready to go when I started the machine. My wife (who rides an F650GS) smirked and commented that the idle sounded much better and she thought the Sea Foam was working. I pulled away and rode for about 3 mins before I had any bars and I noticed that the problem returned about the time the first bar appeared...It was unmistakeable. In one moment it was all good and then the issue returned. I think you're on to something.

Can I ask you to give me the "Trouble-Shooting for Idiots" version of the test process, please? I really do appreciate all the help fellas. If this doesn't work I'll need all the collective experience you have to fix this issue.

Thanks,
Mitch

[roger 04 rt]

Originally Posted by PARATOAD

Roger, I completely get what you're saying. As luck would have it, I was "kitted up" and ready to go when I started the machine. My wife (who rides an F650GS) smirked and commented that the idle sounded much better and she thought the Sea Foam was working. I pulled away and rode for about 3 mins before I had any bars and I noticed that the problem returned about the time the first bar appeared...It was unmistakeable. In one moment it was all good and then the issue returned. I think you're on to something.*
*
Can I ask you to give me the "Trouble-Shooting for Idiots" version of the test process, please? I really do appreciate all the help fellas. If this doesn't work I'll need all the collective experience you have to fix this issue.*
*
Thanks,
Mitch

Mitch,
A bit of explanation and then I'll (or others) will be back with some ideas.

When you get to 1 or 2 bars on a warm day, two things happen at the same time: something called "warm-up enrichment" ends, and your motorcycle goes into Closed Loop operation (and when the throttle is relatively steady). So it isn't easy to untangle what's going on. Take a look at the picture below. I have a Wideband O2 to richen the mixture. On your motorcyle, the picture will look the same but the number 13.5:1 will be 14.7:1 and the 13.2:1 will be 14.4:1 (give or take a bit, depending on air and oil temperature). At the left side of the picture the bike is starting and as it warms in Open Loop, the mixture is getting leaner as the bike warms up. So the next thing to figure out is whether your bike is stumbling on the leanness of 14.7 or whether the O2 sensor is sending a faulty signal leading to a mixture leaner than 14.7. All for now, back later.