1964 CL 72 oil leak

G-Man · Post by **G-Man** » Sun Feb 07, 2016 5:33 pm

It doesn't look to me that the seal is leaking but I do wonder about the hole in the shaft. Are there any oil marks on the back of the rotor, or any other signs where oil might be seeping?

G

LOUD MOUSE · Post by **LOUD MOUSE** » Sun Feb 07, 2016 5:34 pm

I use a metric bolt which I can't for the life of me recall the size and thread.
Maybe 12x1.25 or 12x1.0.
I got it at a hardware store for cheap.
That black thing you see Is The Seal. ................................lm

connor1 wrote:Anyone willing to share their techniques for removing this rotor? Stator came off easily, but this drum with the magnets seems a bit tricky.....

Also behind the drum is a black round cover the shaft passes thru...I am assuming that I will have to remove this cover to get to the seal, and if so what is the best way to remove?

connor1 · Post by **connor1** » Mon Feb 08, 2016 9:37 am

Here is a pic of the back of the rotor, it was dry and clean.

However the crank shaft has a coating of clean oil, and the bottom of the seal has a collection of clean oil in the silicone sealer nooks and crannies. This leads me to think that the seal may be leaking/seeping where the shaft goes through the it OR oil is leaking out of that hole that Gman noticed that is unusual for a CL72, or both.

I will post a couple of other pics showing how dirty and sludgy the other seal area is so you get a feel for the situation, as a indication of where the clean oil is coming from.

I am thinking the best approach may be to replace the crank seal and clutch rod seal, and figure out a way to seal up the hole in the shaft to prevent what may be a source of the leak. Some ideas are some jb weld in the hole, or just the right size machine screw and o ring, or both, any suggestions here?

Also considering putting the cover back on without the rotor and stator installed, kickstarting the bike and then removing the cover to hopefully see where this heavy oil leak is coming from. Not sure if this may cause some electrical issues/problems. I am somewhat reluctant to disconnect the stator wires for fear of breaking them, but will probably have to if I go this route.

You input/comments/advice as always are appreciated.

connor1 · Post by **connor1** » Mon Feb 08, 2016 9:40 am

Some other pics

LOUD MOUSE · Post by **LOUD MOUSE** » Mon Feb 08, 2016 10:09 am

That is a CB72/77 crank but I don't see the amount of oil that would be in the area if it isn't plugged.
I do see what I expect in the area of the sprocket and on back.
It usually comes from the chain as it heats up and the lube fly's off.
Do you lube the chain?. ................lm

connor1 wrote:Some other pics

connor1 · Post by **connor1** » Mon Feb 08, 2016 10:27 am

Yes I have lubed the chain. I use PJ1 for o ring chains. Advertised not to "fly off".

However, in the rear rim a good amount of semi clean engine oil has been collecting, this appears to be coming from the chain.

The clean oil leak that is dripping off the stator is fairly high in volume. A drip every 7 to 10 seconds when running. Do you feel this would be the crank seal only?

G-Man · Post by **G-Man** » Mon Feb 08, 2016 10:44 am

I suspect that someone has plugged that hole from the inside. As LM suggests, you would expect to see a lot more oil if it was unplugged. The oil would run along the shaft and be flung onto the back of the rotor.

It is a common mod for race bikes (where the starter is removed) to block that hole with a brass rod, or fill it with epoxy / JB weld.

From your description it sounds like it is the crank seal that is leaking. Follow LM's advice and chamfer the edge of the bore that the seal fits in. I also like to put some thin tape ove things like the key slot and any other sharp edges when inserting the seal.

G

connor1 wrote:Yes I have lubed the chain. I use PJ1 for o ring chains. Advertised not to "fly off".

However, in the rear rim a good amount of semi clean engine oil has been collecting, this appears to be coming from the chain.

The clean oil leak that is dripping off the stator is fairly high in volume. A drip every 7 to 10 seconds when running. Do you feel this would be the crank seal only?