During really moist weather (not during rides in rain), my 85 K100RS runs but misses. It usually goes away once it's warmed up. The "misses" range from a second or two to 30 or more seconds, this being the period where the thing is not running on all four cylinders -sometimes feels like maybe only two cylinders are firing. At first I suspected it was moisture in the gas, but then figured it might be moisture in the cylinders or injection system somewhere that heats up and goes away. I've read all the other posts about the throttle position switch, but don't think that's it (it's clean and anti-corrosioned)... Is there some other vulnerable switch or maybe just design of the bike that would make it especially vulnerable to high moisture content air/condensation?

I believe HT leads can be a problem on older K's.

Hello and thank you for your "lead"...

I had the ends off at the plugs and the coils somewhat recently and they looked good/shiney/no corrosion -do you suspect that HT leads could still be "intermittently bad during very moist weather" even though they look good? That is, maybe a internal defection in the wire due to age?

Or how about this: can one coil be "intermittently bad during very moist weather" -that is moisture internal to the coil itself?

Back to the symptoms, It's really weird -the bike runs crappy if it's been sitting a week (covered) in moist weather -enough such that I don't bother riding it... Then, after the weather changes, even the next day (e.g., no more moisture on windows), it runs great, like it never missed a beat!!! During the "moist attempts" IT ALWAYS STARTS, but then runs a few minutes and then begins to miss, sometimes, like I said, seemingly on two cylinders -but as it heats up (after a couple stalls/restarts) it runs fine!!! I'm beginning to think I just need to talk to it some more -I do pay it compliments all the time, but have never bought it any jewelry...

Thanks again.

Have you got original leads and bobins on the plugs??

Hi,
Couple of things I suggest that are worth doing, put in a set of new plugs as that establishes a baseline of perfection for them, give the plugs a good dose of silicone spray on the insulators to help prevent the bonding of the rubber boot inners to the porcelain.

Then check the resistance end to end of the leads, they should be approximately the same. Whilst checking resistance waggle the ends about to see if there are any fluctuations in resistance reading as the leads bend about the ends. If that is OK I suggest you give each end a hearty spray with silicone spray as that disperses water and helps prevent it getting back. Do both ends of the leads. Also carefully check the leads for signs of chafing or arcing in case they are shorting down along their length. Once back in place a spray along the bundle of dressed cables is a good idea.

Look carefully at the ignition coils they are known to develop cracks and then become unreliable in damp weather, if there is any sign of cracking I suggest that you give them a good baking for half an hour in the oven at about 110 C (when your wife is out of course) when cool then put High Voltage varnish on the cracks so it soaks in.

If you can possibly rig up some form of bell jar where you can evacuate the air pressure (even with a hand operated vacuum pump like the Mity Vac) and then let the air pressure back in it will then use the air pressure to force the varnish into the the cracks and coils. http://www.mgchemicals.com/products/4226.html or is the sort of varnish I was thinking of. I have done this in the past for high voltage coils. Put some tape around the cracks to form a dam, fill the dam up with the varnish place in the bell jar and suck the air out so as to allow the air to bubble out of the cracks through the varnish. As the vacuum builds up you will see the bubbling stop and then if the impregnating varnish has a boiling point it will start to boil a bit, at that point stop pumping and allow the air slowly back in. Allow a few days in a warm place for drying and put the coils back to work. Should now be fine as long as the moisture is all out. Last thought is treat all the connections to the Bosch engine management and ignition unit, sensors, and throttle flow sensor with DeoxIt.
Regards,
K-BIKE
Below is another varnish
http://www.magnagroup.com/products/corium/pdf/literature/cz202r.pdf

Wow, you guys are good! Rene, if those wires (and bobbins) are original, they're in pretty good shape. However, based on "K-Bike" -cool name, man- says, I think I'm going to think of new plugs (I just cleaned and re-gapped them -they all looked great and consistent) and leads as the jewlery that bike deserves -she's been so good to me, so I think she deserves it regardless of what I find out about the coils, which I will diagnose and repair as necessary based on "K's" great and amazing advice. Thanks to ya'll. I'll post some follow-up if and when I notice any change/improvement in her. Merry xmas and happy new year!