Well,today I took the 1988 K100 out for her first ride in 14 years. It went well and I did around 50 miles locally on secondary roads .Yes,she still needs new rubber and that will happen soon. The only problem ,if you can even call it a problem ,is after a while as the motor gets warm the instruments got fogged up.Has anyone else had this happen?

Known problem with the early instrument clusters as they didn't breathe. Later instrument clusters had vents with Gortex filters on the back of the case that permitted air to enter but not moisture.

I vaguely remember a cure was to put those silica gel packets in the back of the instruments. Another method involved sealing the joining seam with tape.
Regards Martin.

There are two options:

1. Buy laler instruments pod with goretex membrane

2. Drill 2 mm hole at the lowest section of instruments pod like I did and problem fixed. No fog any more.

Regards

Mmm, I tried all the ideas, drilling holes, sealing the whole cluster, fitting Goretex panels, etc; but the only real cure came with fitting a fan!

https://www.k100-forum.com/t3238-a-cure-for-speedo-condensation

Paul.

Drilling worked for me.

robmack wrote:Later instrument clusters had vents with Gortex filters on the back of the case that permitted air to enter but not moisture.

Mmm... LFB would argue with you over that one. I sprayed the inside of my cover with GT85 and then carefully cleaned it all off. It left enough of a film not to distort the view of the instruments but it killed the fogging stone dead.

Found the article on the fogging fix.http://www.motobrick.com/index.php/topic,7870.msg56850.html#msg56850
Regards Martin.

Thanks for all this great input.I knew I'd get the answers I was looking for here.I'm relieved that it is a common thing.I was thinking that perhaps something was happening down in the motor with the cooling system sending moisture up. The bike runs great and I'm feeling more and more comfortable on it as I ride it , learning all it's little noises and things.Yesterday was the first 50 miles,today I ride again and go a little farther but still going slow and on secondary roads. She has a good feel to her. Been 10 years since I got to know a new bike .I'll probably try the drilling out some holes fix soon and see if that works.