Oil leak at crankshaft behind starter clutch

Can this seal be replaced without splitting the engine open? Hoping I can just pull off the starter clutch (maybe called a dynamo?)and gear and replace the seal. 1975 kz400

I dont know what bike you are referring to, but im going to assure youre talking about a 1975 kz400 based on your previous posts. Im pretty sure that there is supposed to be a bit of oil behind the alternator cover to lubricate the starter clutch. Are you sure that the seal is leaking? 

This area is supposed to be dry. No oil passage or return. 
1975 kz400

spyshot wrote:

This area is supposed to be dry. No oil passage or return. 
1975 kz400

 

This has been brought up on the forum previously here .

Here is an oil routing diagram. See how an arrow points into the left cover area.  
I just dont want you wasting your money and time.

Yes, I’ve seen that diagram. It is very hard to see, but I think it’s pointing to the end of the crankshaft inside the crank case. Again, there are no oil passages inside the stater cover and no returns.

I have also read the thread on this, and I disagree with their conclusion. In addition to this, there is a mechanic on YouTube that completely rebuilt one of these engines and also states that this area is supposed to be dry. I ran the engine with the cover off and got no oil at all.

there is an oil seal behind the dynamo/generator. I believe this is leaking on mine and I am in the process of ordering a new one to get it replaced. Must only be leaking when it’s under load or when it gets hot.

thanks for checking up on me though

If you will be replacing the seal then it would be ideal to have an alternator rotor puller tool handy, which if you have watched an engine disassembly, you may already know this. Other than pulling the rotor, getting to the seal is not terribly difficult.

You may attempt to remove the seal without splitting the cases but be very careful to not damage any metal surfaces because then it definitely won't seal. If you cannot remove the seal without splitting the cases, then the seal is probably too damaged and will definitely require the cases to be split.

Be ready for replacing many gaskets, o-rings, and having to assemble the whole engine without damaging anything, such as piston rings, or valves from incorrectly set timing. If you are ready for this though, it would be a great learning experience if you haven't done something like this before.

By the way, care if you share a pic of your bike? I've always wanted one in the old style, but im stuck with my 440.... I guess its good enough 

The easiest way to remove the seal without damage is to screw two self tappers into the face of the seal on opposite sides and work it out with two pairs of pliers

  Thanks for the tips. 

You have yourself a looker! Do you get many head turns when driving?   Wookies advice will help you get it out and when when putting the new seal in make sure that it goes in straight because its a tight fit.

Wookie58 wrote:

The easiest way to remove the seal without damage is to screw two self tappers into the face of the seal on opposite sides and work it out with two pairs of pliers

Plasterboard drywall screws are ideal. They can pierce the inner steel inside the seal. Same method is used for car crankshaft seals. When replacing use a little oil or vaseline and work it in using a correctly sized bar or socket that only impacts on the outside of the seal (same principle as driving a bearing). Note the depth of the original seal before removing and replicate with the new one.

Bound, thank you. I just found that seat on ebay. It is original. Now with the brown seat I feel the need to go red. The blue isn't original anyway. 

Thanks for the advice! If I find that I'm wrong about the "stater cover dry or wet issue" I'll post it up. 

Now a new issue...I'm an idiot. Read through the service manual about the removal of the dynamo/generator, but missed the part about the bolt on the dynamo/generator being a left hand thread...yep, I broke it....what a dummy....

anyway, a regular screw extractor will not work so I'm thinking that a drill bit will grab it and spin out the remainder of the bolt out of the crankshaft. I will try that when I get it back apart again when the seal and new bolt arrives.

one step forward two steps back.

old bikes and an amatuer wrench opperator. I guess that's how these things go.

Adam

• moizeau , Good Idea