Kawasaki Brute Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
34 Posts
Discussion Starter · #1 ·
Im running into something I have not seen before. When I do a compression check of the front and rear cylinders there is a large pressure difference. Front shows about 100psi and the rear shows about 50psi (this is what my service manual shows that it should be). The test was performed with the engine cold, the carbs removed and spark plugs removed.

What would cause the front cylinder to be so much higher than the rear.
 

·
Super Moderator
Joined
·
14,100 Posts
Im running into something I have not seen before. When I do a compression check of the front and rear cylinders there is a large pressure difference. Front shows about 100psi and the rear shows about 50psi (this is what my service manual shows that it should be). The test was performed with the engine cold, the carbs removed and spark plugs removed.

What would cause the front cylinder to be so much higher than the rear.
Sounds like the front has a bad spring on the compression release...or just stuck. The springs hold the flyweights in up to just over 450 RPM where above that they fly-out rotating the release shaft and button. Although it's not common for them to just stick in the released position, it is common for a spring to break or stretch. This is what they look like in the retracted position...meaning from 0- 450RPMs where the release is on:

 

·
Registered
Joined
·
34 Posts
Discussion Starter · #3 ·
Sounds like the front has a bad spring on the compression release...or just stuck. The springs hold the flyweights in up to just over 450 RPM where above that they fly-out rotating the release shaft and button. Although it's not common for them to just stick in the released position, it is common for a spring to break or stretch. This is what they look like in the retracted position...meaning from 0- 450RPMs where the release is on:

OK Thanks, I will pull the front rocker cover so I can get to the front cam and see if I can see anything. I appreciate the help.

Colton
 

·
Super Moderator
Joined
·
14,100 Posts
OK Thanks, I will pull the front rocker cover so I can get to the front cam and see if I can see anything. I appreciate the help.

Colton
Yeah that's the tough part...seeing it. Some say they have snaked a small bore scope around to inspect the springs and bolts. Never done it myself but I can see it's possible.
 

·
Registered
Joined
·
34 Posts
Discussion Starter · #5 ·
I pulled the cam to give it a good look and the spring and bolts look fine. One thing I did notice it looked like the cam was 180 degrees off. Could this account for high compressions??
 

·
Super Moderator
Joined
·
14,100 Posts
No..i
I pulled the cam to give it a good look and the spring and bolts look fine. One thing I did notice it looked like the cam was 180 degrees off. Could this account for high compressions??
Probably had it on TDC of the exhaust stroke instead of the compression stroke. The marks line up both ways.
 
1 - 6 of 6 Posts
Top