K11 LT engine sounds & acts funny in the rain

[basketcase]

Recently I got caught out in a rain storm, and when the engine cooled (while riding), it began to act up.

- Misfired
- Hesitated
- Made a “clattery” noise

At first, I thought I had blown an exhaust gasket, but then I realized the sound stopped as the rpm’s increased.

Prior to the rain, the temperature gauge was at about half-way. After the radiator got wet and it began to cool, the gauge dropped down to just above the blue marks. That is when it acted up. As long as I was able to keep the temp (needle) 1/4 and above, no problem.

I thought it might be a problem with the thermostat. A friend commented that, perhaps, a sensor is malfunctioning and the engine is running too lean for the temperature (i.e., when riding in the rain)..

Either way, I don’t know, but need to.

Thanks in advance,
Rick

[CustomSarge]

That seems to be too large a change in temp just due to evap cooling in rain. My '93 changes but not even close to blue/cold range. I'd want to be certain of radiator fluid level first. That it runs ok with temp at 1/4+ sounds right for a warm engine. Good hunting <<<)))

[deilenberger]

Originally posted by RickM
Recently I got caught out in a rain storm, and when the engine cooled (while riding), it began to act up.

- Misfired
- Hesitated
- Made a “clattery” noise

At first, I thought I had blown an exhaust gasket, but then I realized the sound stopped as the rpm’s increased.

Prior to the rain, the temperature gauge was at about half-way. After the radiator got wet and it began to cool, the gauge dropped down to just above the blue marks. That is when it acted up. As long as I was able to keep the temp (needle) 1/4 and above, no problem.

I thought it might be a problem with the thermostat. A friend commented that, perhaps, a sensor is malfunctioning and the engine is running too lean for the temperature (i.e., when riding in the rain)..

Either way, I don’t know, but need to.

Thanks in advance,
Rick

As Sarge pointed out - the change in temperature is more than would be expected from riding in the rain.

I'd have to suspect an electrical problem that is both causing the engine to misfire at lower RPMs, and causing your temperature gauge to read low.

And running too lean for the temperature is unlikely - the mixture is richened when the engine is cold.

If you're worried that the engine IS actually running too cool, I'd want to check the temperature of the coolant to see if the thermostat is any good.

Not too simple to do, I have an electronic thermometer that has a remote probe - one from Radio Shack might work if it will read that high.

Center on the gauge is about 200-210F (from memory), first hash mark to the right of center is ~230F and just above that is where the fan is switched on at 240F.

But - given the symptoms - it appears much more likely that there is an electrical problem made worst by getting wet.

HTH,

[bmwmick]

Rick,
I have a coupla questions....Does your bike usually take a long time to warm up to operating temp? I had a problem on my '93 LT where the thermostat had slipped out of the rubber O-Ring it's mounted in and it tilted sideways. That allowed coolant to flow ALL the time and it would take forever to warm up. I replaced the thermostat and rubber O-Ring (it comes with the thermostat) and that cured the warm-up problem. You should get to about 1/3 of the temp gauge in 15 minutes of riding or less.
The other thing I've noticed is that if I get a lot of water up by the coil assemblies, the bike will run rough for a few minutes. I've pulled the wires out of the coils and smeared the inside of the caps with a little silicone grease. I use the same stuff for the spark plug ends.

Mick:brow

[basketcase]

Mick, this is my third K bike, and I would say the bike warms up "normally."

The coolant was changed at the 24 k service, and would not normally be due again until 36 k. I might go ahead and do it when I do them all this fall.

I suppose the most elementary way to see if fire is jumping someplace is to expose the coils and wiring, and then start it up at night in the driveway. If there is not any fire jumping anyplace (indicating a short, or broken insulation), then your silicone grease trick might do it.

Can you suggest a name brand on the type of lube/sealer you would use?

It will certainly be worth a try. Meanwhile, any other suggestions will also be appreciated.