Engine advise please
Posted: Sun Dec 17, 2017 10:43 am
Hi, So I did compression test on my cb650:
Results were:
1: 140 psi
2: 90
3: 75
4 90
The story was this engine was rebuilt by a Yamaha tech....
so I have taken off the head and it’s now on the bench with the chambers filled with diesel to see if the valves are leaking. To be fair they don’t seem too bad.
I have been inspecting the pistons and rings which I have a few questions about.
According to the manual the top ring is has this profile [] and the lower ring is like [\ but my top ring has have a chamfer on the top of the ring they are also marked R & RN my feeling is the rings are not on the piston in the right order. I have checked the ring gaps which are 0.30 - 0.40 so we’ll in tolerance.
Can anyone enlighten me on the rings?
Thanks
Results were:
1: 140 psi
2: 90
3: 75
4 90
The story was this engine was rebuilt by a Yamaha tech....
so I have taken off the head and it’s now on the bench with the chambers filled with diesel to see if the valves are leaking. To be fair they don’t seem too bad.
I have been inspecting the pistons and rings which I have a few questions about.
According to the manual the top ring is has this profile [] and the lower ring is like [\ but my top ring has have a chamfer on the top of the ring they are also marked R & RN my feeling is the rings are not on the piston in the right order. I have checked the ring gaps which are 0.30 - 0.40 so we’ll in tolerance.
Can anyone enlighten me on the rings?
Thanks