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Engine Knock On K100 engine

z3beemer

New member
I have a 91 K1 with about 28,000 miles on it. The bike doesn't get ridden much but I decided to take it for a short ride the other day. When I got back, I noticed a knock coming from the right side of the engine near the front. When I rev it up it doesn't seem to get any louder but it doesn't go away. The bike starts right up and idles smooth. I took it for another short ride but could not tell if it was knocking or not, I couldn't hear it knocking on the road. I checked the oil and it's clean and OK. I had no problems with the bike until now and it happened all of a sudden. Any thoughts? Would I do serious damage to the bike if I continue to drive it? Are there any other forums out there that specialize in K-Bikes? Any help would be greatly appreciated. Would like to ride it a few times before winter sets in.

Thanks
 
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It could be the rubber drive insulators (monkey nuts!) on the alternator that have deteriorated allowing the metal drive fins to contact the driven fins.
 
Any other thoughts on this before I go blindly tearing into the engine? Any help will be greatly appreciated.
 
I would try to better isolate the source of the sound and post the findings.

There is a wealth of knowledge here and I suspect that you can get a good idea of what to check and how to check it so that you do not have to go blindly into anything.

Try using a screwdriver as a stethoscope to listen to specific "parts" to see if there is anything specific that seems to be making the sound in question. Place the business end of the screwdriver on the part and your ear on the end of the handle. Be careful of hot, moving and/or electrical components.
 
You can buy a cheap mechanics stethoscope at Harbor Freight. Alot easier to use than the screwdriver method, though that does work.
 
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