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Discussion Starter #1
I have a '90 VN750 B2 with 36K on it. Today I was cruising at about 65 mph and I noticed a change in the engine sound. It got louder and sounded like a chain rattling. I pulled over and immediately noticed oil just pouring out of the left lower side of the motor, the clutch housing, along the seam of the case. I shut it off and it dumped all of the oil it had. As I watched the oil stream out of the bike I saw pieces of the gasket falling from the bike too. I have not started it since. Before I crack this thing open, does anyone have any suggestions as to what to look for. It was running beautifully right up until the leak. I had ridden about 30 miles at highway speeds. I am fairly handy with a wrench (adjusted the valves and replaced a timing chain on a KZ750), but I have never worked on this bike other than replacing the final drive last year. Am I going to find terrible things? Any help would be appreciated.
 

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The clutch housing is on the right, not the left.

Are you sure the case isn't cracked or broken? Gaskets rarely blow out, but of course can.

If it's the Left side in front of the left footpeg, you might have a fragged balancer....which has been known to blow right through the lower engine case.

Would not try starting it untill you find out what's wrong.
 

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Linkmeister Supreme
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Welcome to the Vulcan madness nothreat.

Oil pouring out of the lower left side of the engine case sounds like the balancer gear chewing a hole through the case. The balancer dampers are probably worn out and falling apart. Have you been seeing any rubber chunks in the screen behind the oil drain plug on the lower left side of the engine when doing regular oil changes?

Here is a link to jthills teardown and rebuild of a basketcase engine about 3 years ago, --Part 1--And The Journey Begins.
There are lots of pictures of the broken cam chain, a holed piston and other stuff you don`t want to see in your engine. :(

There is a picture of the balancer gear in post number 41.
http://www.vn750.com/forum/showthread.php?t=10466
Follow the links to the 2nd and 3rd threads in his series, -The Journey Continues, and The Journey Ends.

Roach made a whole series of videos chronicling his teardown and rebuild too:
http://www.vn750.com/forum/showthread.php?t=18289

This should give you a pretty good idea of what the inside of this engine looks like. :smiley_th
 

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Discussion Starter #4
Got the bike home and looked at it more carefully. I think the balancer is the problem. Based upon your suggestion, the grinding sound, looking at the videos, the metal flakes mixed in the oil on the case, and the crack in the case that has to be the problem. The case has a crack in it to the right of the gasket seam. It is not wide open, but is cracked. My manual says I have to pull the engine. Is this as big a job as I think it will be? I am pretty sure I am not a good enough wrench or have the tools to tear the engine down. I also imagine the right balancer should be checked and replaced too. This is a 1990 with 36K on it. Is it worth fixing if I have to have it done?
 

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Sparky!!!
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There is a basket case part out going on.. see if he has the engine... and ask him what is wrong with the engine... It would be worth it, if you can find the parts used. and you pulled the engine your self. if you have a few wrenches and sockets, a cross tip and flat blade screw driver you should have enough tools to pull the engine... ohh and a milk crate.
 

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Linkmeister Supreme
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Got the bike home and looked at it more carefully. I think the balancer is the problem. Based upon your suggestion, the grinding sound, looking at the videos, the metal flakes mixed in the oil on the case, and the crack in the case that has to be the problem. The case has a crack in it to the right of the gasket seam. It is not wide open, but is cracked. My manual says I have to pull the engine. Is this as big a job as I think it will be? I am pretty sure I am not a good enough wrench or have the tools to tear the engine down. I also imagine the right balancer should be checked and replaced too. This is a 1990 with 36K on it. Is it worth fixing if I have to have it done?
The right balancer does not have the rubber and plastic dampers in it, so seldom needs maintenance or replacement.
See diagram in link:

http://www.cheapcycleparts.com/model_years/2674-kawasaki-1991-vulcan-750-vn750-a7/assemblies/74225-crankshaft
 
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