starter problem

[Tridentested]

I am recommissioning my 81 R100CS after a couple of years sitting in the garage. The old battery was shot so replaced with a new 20amp AGM one. On trying to start the bike the starter motor just goes 'clunk' and refused to turn the engine over. In case the engine had seized I removed the plugs and squirted WD40 down the plug holes. Pushing the bike in gear I was able to turn the engine. But still no joy with the starter. Is this a case of a stuck starter or what. Any ideas please as to cause and solution

 

[KMD]

Sounds as if the solenoid is pushing the drive gear forwards to mesh, but the motor is not spinning. Seized motor inside the starter?

 

[albatross]

I am recommissioning my 81 R100CS after a couple of years sitting in the garage. The old battery was shot so replaced with a new 20amp AGM one. On trying to start the bike the starter motor just goes 'clunk' and refused to turn the engine over. In case the engine had seized I removed the plugs and squirted WD40 down the plug holes. Pushing the bike in gear I was able to turn the engine. But still no joy with the starter. Is this a case of a stuck starter or what. Any ideas please as to cause and solution

Remove the starter would be my next step and check what it looks like.
Most of these older starters can be taken apart and cleaned greased etc
You can overhaul starters with kits eg from Motorworks if possible.

 

[Gelandestrasse]

Further down the list of possibilities is the battery cable is so corroded it does not allow the current to reach the starter. The ends might look ok but if you peel back the outer sheath and see green stuff.....

 

[theoneandonly]

s/motor out , and check it in a vice .

separate your problems.

 

[Tridentested]

s/motor out , and check it in a vice .

separate your problems.

Thanks for all your advice guys. I'll take the starter out and check it then report back