Drops cylinder when wet

[Russ - deeppurple52]

When I wash our R1100RT it will only run on one cylinder until it get warm (dries out?). It does this every time. It will sput, pop and backfire and the other cylinder with intermittantly cut in and out until I ride a few miles. Any ideas?

[T__]

Russ, lots of ideas but nothing positive about any of them..

 

Possibly:

 

A bad,, cracked,, or tracked spark plug porcelain (cheapest & easiest to replace) so start there..

 

Or, the plug wire from coil to spark plug (may be arcing to something or cracked insulation.. (look for worn spots or a place where it is rubbing on something).. Or just replace it.. Look at the R/H side for the plug wire to be contacting the TBI cam..

 

Or, very slight possibility the coil itself.. Seeing as the same coil sparks both spark plugs kind of unusual to have the coil only effect one side but a cracked output tower or other area effected by water could take out only one side.. (look here last).. Make darn sure the plug wires are FULLY seated in the coil towers..

 

Are you SURE it is only one cylinder.. It is possible that the HES is acting up & you just have an intermittent spark to both sides..

 

 

Twisty

 

[moshe_levy]

I had the same problem. Couldn't figure out what it was. Coils were good. I replaced them and the HES for good measure, and the problem still continued. Turns out it was a 10 cent o-ring on the oxygen sensor that had rotted out, allowing water in. The symptoms are exactly as you described, which are to my understanding usually caused by what Twisty described also, lending to the confusion. But I'd check that O-ring first, since it's the cheapest fix if that's indeed the cause!

 

-MKL

 

PS - mine is an '04 R1150RT - not sure of any differences on oxy sensor vs. your 1100.

[T__]

MKL, that is a strange one.. Any idea what/where that “O” ring went?

 

The 02 sensor on the BMW doesn’t really use any “O” rings.. The seal to the exhaust is a metal gasket & the upper connector is more like a urethane seal (way more than 10 cents).. Unless it was a wire seal where it (wire & terminal) enters the connector body (those would be difficult to pull apart & check though)

 

The 02 sensor is different on your 04 than the older 1100 but the design is about the same (just a different connector style)..

 

Twisty

 

[moshe_levy]

Twisty-

 

Yes, you're right, I used the wrong terminology. It was what you describe as the "wire seal." This was actually handled by the dealer, who couldn't diagnose the issue and went a little hog wild replacing things - coil and HES, which ran me a pretty penny. They told me the bike was finished after coil and HES replacement, but when I came to pick it up, I ran a garden hose all over it, and sure enough, the problem returned. The tech was frustrated and confused, but we went over it all again together, and found water was able to penetrate the o2 connector body. They replaced the "wire seal" and the bike passed the garden hose test, and has been perfect ever since.

 

-MKL

[T__]

MKL, that makes perfect sense now.. I have seen the same issue on automobiles where the 02 connector will take in some moisture (especially salty moisture).. As a rule it doesn’t get better as you operate the vehicle though as once the moisture gets in I can’t easily get out,, but moisture can do strange things to low voltage circuits..

 

His 02 sensor uses a different type connector than your bike does but the wire seals are similar in construction..

 

Sure wouldn’t hurt to check that area..

 

 

Twisty

 

[Russ - deeppurple52]

Excellent advice guys. I will check it out in a day or two. Location of sensor?

[T__]

R/H side just rearward of the fuel tank & just under the rear edge.. Look for it as sometimes it wil be left loose or straped in a different location from a previous repair..

 

 

Twisty