stopping gasket leaks

I have a 1982 KZ650 CSR with 9100 miles which I brought back to life March of 2025. Runs great! I put less than 100 miles on it just to check it out and make final adjustments. Then put it away for the year, but still rode it a very little once each week or two. No issues, no leaks. Then I loaned it to my son who wanted to get license and start riding. He's put 2-300 and now he gets a small amount of oil on the toes of his boots when he's out for 30 minutes or more. Looking closely there my be a very small amount coming from the two side covers. I see nothing from other mating surface of the engine unless I missed. Is there normally oil in the alternator or ignition chambers? Or there shouldn't be and if there is I have an engine seal issue? I see there are gaskets for these covers. Are they just for dust or oil seals? Secondly, if there are leaks I know seal and gasket replacement is the ultimate solution, however, since these leaks may due to dried out gaskets, would a high quality oil stop leak additive be a possible solution to try? There are some that could be used in a wet clutch application that wouldn't cause it to slip. Thx.  

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PS  Nice looking bike

Generator chamber does have oil in it, ignition chamber should not. I have my doubts that any "wonder" additive product will turn back 40 years of aging !!!

good looking bike, wish the 81 I have looked like that when I found it, unlike 900/1000’s alternator is dry, crank seals only, gaskets and seals and gaskets, under sprocket cover could be issue

Thx Wookie58. The Clymer manual for this bike refers to the left side cover as for the alternator and the right side cover as for the ignition. If by "generator" you mean the alternator, then it seems odd there should be oil in there as you state unless I have a seal leak. jwfels says the alternator is dry. I need to try to find the leaks conclusively. Using bright flashlight and very careful inspection, I could not be certain. Any suggestions or tricks for finding small oil leaks? Thx. 1st and 3rd pics alternator cover, 2nd ignition cover.    

Sometimes for small leaks, cleaning with brake cleaner then dusting with chalk dust or talc will help to pin point the source. On the bigger engines the oil in the generator helps cool the stator windings

From what my eye spies, it's leaking from the top down. Could be from the cam cover/half moons or hopefully not, the oval orings which are sandwiched between head and cylinder at outsides of assembly. Also look for gushing oil from your tachometer drive, bad seal/oring perhaps? When engines get hot and you're riding with wind blowing, hot less viscous oil can travel everywhere. 

asphalt900 wrote:

From what my eye spies, it's leaking from the top down. Could be from the cam cover/half moons or hopefully not, the oval orings which are sandwiched between head and cylinder at outsides of assembly. Also look for gushing oil from your tachometer drive, bad seal/oring perhaps? When engines get hot and you're riding with wind blowing, hot less viscous oil can travel everywhere. 

Agree.  Oil dripping down from above.

 

if the leak is coming from the generator. it's probably the crank seal. afaik, it should be dry in there. the Big Kaws are wet. I've only had the generator cover off once on my csr and it was dry. that I remember. ha ha. it's been a while.

That looks just like when my front left half moon was leaking.

The rubber "half moons" on a 650/750 generally don't leak as the cam cover bolt goes down thru the center. It could leak thru the thread if the bolt backs off, easy enough to fix with RTV or 3Bond on the threads.

The 650/750 cranks seals generally don't leak on either points or stator ends. As the stator is "dry" its very easy to check.

It could be a head gasket leak as they operate with pretty high oil pressure to the top end.

If you had the top end apart you really have to stay on top of torquing the head nuts several times during the break in period.

Never ever run oil additives meant for cars in these engines.
 

My best guess it is a head gasket leak. Clean the engine and run it. Look for oil leaks every few minutes, trying to spot the leak where it starts.