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Discussion Starter · #1 ·
My buddy has a 99 ZX7R with what looks like a top end oil leak. We took the fairings off chasing a coolant leak and tightened a hose clamp that wasn't snug and solved that problem.

Upon further inspection we found the left side of the engine has a light coating of oil on it. We cleaned it up and let it run for about 10 minutes and it did not leak. It sat for about 3 hours before checking again. I found another coating of oil collecting on the side of the crankcase, but it looks like it's coming from the cylinder head bolt (is it even possible to weep from the head bolt?) or from somewhere higher? Maybe cylinder head cover?

Trying to come up with ideas to locate the oil leak without tearing the bike down first. I was thinking give it a good cleaning with carb cleaner and a degreaser, let it dry, warm it up and toss some flour/powder on the engine and see if it'll give us an idea of where it's coming from?

Reason I don't want to tear it apart and just start digging, my buddy is on a tight budget and I don't want to make expenses higher than they need to be to repair.

I
 

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I would start by checking the cover gasket. Remove the cover and clean everything up really well. While you are in there, make sure that the cam chain stopper mounted to the cover is in good shape and seated properly. I have seen two where the stopper is not seated and pushes the cover up ever so slightly to weep oil. If that is fine then put it all back together and make sure the torque is correct on the bolts. One of the ones that I've seen weep oil was my own (after it's first and only visit to the dealer), so I know what a pain it is to chase a small leak. Not expensive to do, just takes a little time and some patience. Gasket is re-usable (if it is not damaged and the source of the leak) and the stopper (if it needs replacing) costs about $10.

:crazyloco
 

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Discussion Starter · #3 ·
Thanks for the help.

I took a closer look and can definitely see it's coming from the cover on the clutch lever side of the engine.

So from looking quickly it looks like the tank cover has to come off and then the fuel tank has to come out? Any tips on preventing fuel spills? Easy way to drain the tank?

This will be my first time tearing into a motorcycle so any advice or a brief walk-through would be awesome.
 

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Not sure what you mean by tank cover? Just turn the fuel petcock off, pull the hose off (little bit of fuel left in the line will spill so have a rag over it). Take the four tank mounting bolts out and remove the tank with the gas in it (just keep it level to prevent spills through the cap vent). There will be the vent hose hanging down the left side of the bike, just pull it up as well as it is attached to the tank. Now you will need to remove everything on the cover to access it (should have a manual for it as there are numerous pieces to come off).Airbox, emissions crap, wires and baffle plate on top of engine all need to be removed. Not very hard to do if you have the manual to show what to do. Hope this can get you started anyways.

:smile
 

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Discussion Starter · #6 ·
I was assuming the tank had a fairing over it and was not one piece. Like I said, first time digging into a motorcycle.

The petcock is the round dial on the side of the bike that says on/off/res?

Someone sent me a manual, just haven't gone through it yet. Thanks for the help. :banghead
 

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Thanks for the help.

I took a closer look and can definitely see it's coming from the cover on the clutch lever side of the engine.

So from looking quickly it looks like the tank cover has to come off and then the fuel tank has to come out? Any tips on preventing fuel spills? Easy way to drain the tank?

This will be my first time tearing into a motorcycle so any advice or a brief walk-through would be awesome.
You do not have to drain the tank. You simply turn the fuel off, get a small container to catch fuel and a shop rag.

Unhook the line at the tank with the rag in your hand/around it. Then just bend the hose into your container to get most of it. Wrap the rag around the hose and stick it somewhere it wont be messed with.

If you really insist on draining the tank, you can pull shut the fuel off, pull the hose off the FILTER (again with your rag in hand) but you will wind up with about all of that fuel on your rag.

Then just run the hose from the tank into a bucket.


But the tank has to be almost entirely removed in order to do it either way. So just go with the first method, keep the stuff in the tank, then set the tank on a shelf/floor/bench out of the way where it is safe.
 

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On a 99 you should have a vac activated petcock. You shouldn't leak fuel..
Oh, and... No.

At least, my 97 sure doesn't. Did they add that later on?
 

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Discussion Starter · #12 ·
Thanks.

It took us a total of about 3 hours to tear the gas tank, air box, the plastic shield on the valve cover and the valve cover itself off and to put back together.

I inspected the gasket real well and it looked good on the top side. It was 'stuck' to the cylinder head so I didn't want to stretch it or tear it since we're playing with a tight budget. I cleaned it the best I could and instead of there always being a thin coating of oil on the crank case, there is just a small leak. If we let it run for a while and then sit for some time, a blue rag will barely show oil touching on the corner it was leaking.

I think we will settle with this amount of oil leak for now. My buddy has rode the bike all of 3 miles so we still don't know how well she runs after it gets hot and overall reliability. I think tearing it all down again to replace the gasket without knowing how reliable the bike is would be overkill, afterall I think it would be better to fix a few things at once?
 
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