1150 RT sudden increase in surging

[jeinloes]

I attended the rally and afterwards took a trip through Canada on the north shore of Lake Superior. Couldn't get gas higher than 91 octane and the bike had a lot of spark knock until we could fill up in Michigan with 93 octane fuel.

On the last few miles of the trip home, my bike began to surge in every gear and at RPMs from 2500 to 5000. Very unusual.

Took it to the dealer and he re-adjusted the thottlre bodies after checking for faults. It is still surging.

Any suggestions short of the installation of a Techlusion (which I'm prepared to buy)? I'm thinking Chevron fuel injector cleaner next; maybe new plugs.

Thanks.

Jim

[rayadams]

my 1150 has started running "choppy" at idle and just off idle. I have syn'ed the throttle bodies, which did straighten it out. Then after four hours of riding it started running odd again. I've got to re-syn the TBs again. I suspect there is a problem with the bowden cable "distrubutor" block. The right side is "lazy". Also the left headpipe turns cherry red at idle. Anyone have any experience with this.
Ray

[james1300]

I attended the rally and afterwards took a trip through Canada on the north shore of Lake Superior. Couldn't get gas higher than 91 octane and the bike had a lot of spark knock until we could fill up in Michigan with 93 octane fuel.

On the last few miles of the trip home, my bike began to surge in every gear and at RPMs from 2500 to 5000. Very unusual.

Took it to the dealer and he re-adjusted the thottlre bodies after checking for faults. It is still surging.

Any suggestions short of the installation of a Techlusion (which I'm prepared to buy)? I'm thinking Chevron fuel injector cleaner next; maybe new plugs.

Thanks.

Jim

Possiable vacume leak? Did that dealer really hand you back your bike and claim its fixed??

[jeinloes]

Possiable vacume leak? Did that dealer really hand you back your bike and claim its fixed??

No he really didn't claim it was fixed. He too thought about the vacuum leak, but at the time I brought it in, he really wasnt able to do other diagnostics while I waited. The fact that the throttle bodies were out of adjustment made us both believe that that may have been the problem.

[NN9S]

I don't think the 91 was causing your problem. I use to burn 89 (mid grade) in my 04 R1150RT all the time with no notable loose of power, ping, bing, etc.

[bikerfish1100]

i was having a heck of a time trying to sync my TBs last year- would get them spot on, and they'd be out and stumbling again in just a few hundred miles.
here's what i found... BBS fresh out of the bike
http://i132.photobucket.com/albums/q13/bikerfish1100/just%20bikes/dirtyBBS.jpg
BBS after cleaning..http://i132.photobucket.com/albums/q13/bikerfish1100/just%20bikes/cleanBBS.jpg
that was with around 45K on the bike.

[james1300]

Does it just unscrew? Whats its purpose?

[bikerfish1100]

you're looking at the business side of the BBS (big brass screw)- the thing you adjust to set idle speed (on left) and to sync the TBs together. It just unscrews from the TB. Before removing, thread it in until it stops, counting how many turns you made from it's initial setting. That will give you a reasonable starting reference point when you put them back in.

[kbasa]

When was your last valve adjustment?

[AZgman]

Also, make sure both plugs are still tight. They have a way of working loose... don't ask me how I know!

[jeinloes]

When was your last valve adjustment?

Had one at the 42K service in May, 07.

[RT Pilot]

I also have an '04 1150RT that has started surging a little this summer and for what it's worth, I have a theory. . .I've noticed that surging complaints on the forums increase during extremely warm weather--and it's been a scorcher around PA for the past week or so.

I believe that under extremely hot operating conditions the Motronic ECU operates at an extreme "range" in the fuel mapping that it wouldn't go to in cooler ambient temperatures. This high ambient temp "range" in the fuel mapping attempts to force an even leaner condition than normal to compensate for the extreme heat (fuel / air mixture settings vary greatly depending on air temp, because air is LESS dense when it's hot and more dense when it's cold).

Because there are fewer molecules of air (by volume) in our extremely hot ambient temps, the Motronic will attempt to add even less fuel to force the 14.7:1 fuel mixture that it always wants (at certain power settings), but it's possible that the air is so warm that it's not possible to achieve that mixture without causing poor engine performance / operation; or it's possible that the Motronic wasn't programmed to operate accurately above certain temps. I'm open to suggestion or other ideas, but I thought I'd throw that out there as a possibility.

Anyway, I'm willing to bet that in a couple months, surging complaints will dwindle as we head into the cooler fall temps--I know my RT seems to run much better when it's cooler out.

[DrPaul]

I've had this same thought. I ride my '02 R1150RT to work almost every day when weather permits. There is always less surging in the mornings (temp~70) than in the evening (temp~90). And, it is more noticable at slower speed as small variation in engine RPMs is magnified in the lower gears.

Paul

[RT Pilot]

Yep. . .same observations here about the morning commutes, but you also have to factor in that the ECU is dumping more fuel into the mixture (richer) until it comes up to full operating temperature--it always runs better before the engine temp comes up to normal ranges.

I wonder if some of the engineering types on the forums could come up with a way to "fool" the OAT (outside air temperature) sensor in the air box into sensing that the ambient air temp is colder than it really is. . . .then the Motronic ECU would consistently dump more fuel into the mixture to compensate. OK guys, is this possible?

Rob

[Red100RT]

I think you guys have hit on something here. My 04RT began surging on a ride several weeks ago in very hot weather. I lost my mind and bought a Techlusion R259/1032 and performed a very careful TB sync and valve adjust before installing the Techlusion. The TB sync and valve adjusts have never made any difference in the way the bike performs in the past but then surging has never really been a real problem. The Techlusion has eliminated surging, improved cold and hot starting, made shifting much smoother as the revs don't drop as fast when de-clutching. I just wish I would have gone the Techlusion route 24K miles ago.:banghead

[jeinloes]

I think you guys have hit on something here. My 04RT began surging on a ride several weeks ago in very hot weather. I lost my mind and bought a Techlusion R259/1032 and performed a very careful TB sync and valve adjust before installing the Techlusion. The TB sync and valve adjusts have never made any difference in the way the bike performs in the past but then surging has never really been a real problem. The Techlusion has eliminated surging, improved cold and hot starting, made shifting much smoother as the revs don't drop as fast when de-clutching. I just wish I would have gone the Techlusion route 24K miles ago.:banghead

Was the Techlusion easy to install?

[Red100RT]

Jim, to answer your question was it easy to install? Yes, could not have been easier. Take off right side tupperware and the rest is as easy as changing a light bulb.

[jeinloes]

Jim, to answer your question was it easy to install? Yes, could not have been easier. Take off right side tupperware and the rest is as easy as changing a light bulb.

Thanks. By the way just heard from the dealer. Says the fuel pressure is 25% over specs. Opposite of what he thought he'd find, given the symptoms. Anyone ever hear of that?