2008 R1200RT - Intermittent Rough Running

I took my RT to the Rally and along the way (in Cheektowaga, NY) filled up with Sunoco 93 octane fuel. I noticed that the engine started to seem to struggle some and ran slightly rough. It also had a sharp decline in indicated (on the BC) MPG. I stopped in at BMW of Grand Rapids and the SM there told me that it sounded to him as if I'd gotten some bad gas.

After consulting with Omega Man (thanks Gary!) I began adding Sea-Foam (1 ounce per gallon) at each fillup. That seemed to fix it, and pretty soon it was running mostly fine, but the symptoms return apparently at random. Sometimes it runs rough for 50 miles, then clears.

I continue to add Sea-Foam, and when I run out of that, I will switch to Star-Tron. I believe I got some non-ethanol gas in MI and MN, and that seemed to make it run better.

In terms of history, the bike has been maintained by BMW dealers exclusively and according to the schedule. Its most recent work was the recall on the fuel system, and the fuel pump was replaced at that time.

I'd sure like to hear if anyone else has had this kind of problem, and hope that someone has had a solution.

TIA - JG

I use Seafoam in my 07 RT and on about half the rides I take, I have a can with me. I was "encouraged" to try Star-Tron. I wasn't impressed. Bike runs smoothest with a can of Seafoam [bike has fuel cell] about every fifth fuel-up. I have about half a dozen cans in the garage most of the time because a buddy that works at NAPA calls when it's on sale for $5.00 a can.

I look at it this way: if Seafoam can handle marine fuels and the amount of condensation that application sees, it can sure handle the occasional crap tank of fuel I may get on the road.

With over 100K on the bike - I'd guess something I'm doing is working.

It doesn't sound like fuel since it has been a while. Stop in at the GS-911 booth and ask them to put their new 911 wifi on your bike and see if it has produced any error codes. Maybe they would look at your sensors too.

You could also ask them to reset your adaptive values.

SteveAikens said:

I look at it this way: if Seafoam can handle marine fuels and the amount of condensation that application sees, it can sure handle the occasional crap tank of fuel I may get on the road.

With over 100K on the bike - I'd guess something I'm doing is working.

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I'm at 82,000 miles and have never used Seafoam. Used Techron once or twice. Just because I had it. Used StarTron once when I went away for 6 weeks. What I'm not doing seems to be working about as well as what Steve is doing.

As far as the OP's problem - almost sounds like a failing coil or plug. Unfortunately the ECU on the Hex/Camhead bikes doesn't record misfires - so it's a bit harder tracking this down. I've also had similar (but I don't think as bad as OP's) behavior when I had an O2 sensor fail..

There was an old saying in the British car circles back in the 60-70's.. Carburetor is a French word meaning "It's the ignition dummy..." IMHO I think that's still fairly true today.

check valve adjustment

I had this problem recently. I really didn't worry about it since it was not significant. However during a routine valve check I found a couple of the valves slightly off, I adjusted them and when the roughness disappeared. Worth a check!

Thanks to all for the replies. I am about 1000 miles from home at this point, and 90% of the time it's running fine. I made a two-hour trip in heavy rain today, and it ran flawlessly. It'll be due for a 6K service when I'm back in MA, so I will present your ideas when I bring it in. On the 'phone today, the SM at my dealer surmised that it was water in the fuel (possibly introduced in Cheektowaga), and may require a tank drain and other measures to correct. Time will tell.

Thanks again - JG

Define rough

Do you mean it idles a bit rough or are you experiencing an engine miss/ lack of power?
I use the friendly to catalyst and sensors octane boost at every fill-up. My 08 RT runs smooth and flawless with Chevron 91 octane and the boost.
Maintained by my loving hands since birth.

ExGMan said:

Thanks to all for the replies. I am about 1000 miles from home at this point, and 90% of the time it's running fine. I made a two-hour trip in heavy rain today, and it ran flawlessly. It'll be due for a 6K service when I'm back in MA, so I will present your ideas when I bring it in. On the 'phone today, the SM at my dealer surmised that it was water in the fuel (possibly introduced in Cheektowaga), and may require a tank drain and other measures to correct. Time will tell.

Thanks again - JG

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Good Luck getting home. It weighs on me when I suspect something maybe wrong which causes me more mental fatigue.

Back Home Again

I started adding Star-Tron to the gas (about 1 ounce at each fill), and now it's running fine. The last 1000 miles were run mostly at 4000 rpm (equating to ~72mph in 6th gear). Bike consistently got 50mpg and was butter smooth with plenty of power. I hope my troubles are behind me, so to speak...

50 MPG????? I never get better than 43! on my 08 RT.
I ride very conservative and I have always averaged 43/44 MPG. California gas?

50mpg

Cookie - I got my 2008 RT when it had 2200 miles on the ODO. It now has 40,782 on the ODO. It has been pretty consistent at about 46 MPG around town, and 50mpg on road trips, i.e. out of stop and go traffic. I am located in MA and most of the time it gets 10% ethanol blended 93 octane stuff. On a couple of road trips out to the West I used some 91 octane 100% gas, i.e. no ethanol. The engine seemed to like that a lot and delivered 54 mpg.

I too am a conservative rider (except when passing slow cars on US2 in the Upper Peninsula of MI on my way to the St. Paul MOA Rally).