shadtews
Member
Hello, everyone,
I am in the middle of rebuilding the motor on my 1968 CL77. I am currently working on the valves and was hoping to validate a few things before I proceed.
First, I did the liquid test and found that all of my valves were leaking. Not too surprised as the bike sat for a long time and I had to do a lot of carbon and rust cleanup. After cleanup, I lightly lapped the valves and that seems to have stopped the exhaust ports from leaking but the intake valves are still allowing the liquid to bypass. At this point I want to get the seats redone and replace the valves if they need it. Although I know a machine shop that can perform this service I'd like to give it a try myself in hopes I can do the same on future rebuilds.
So first question. The FSM says the "Cylinder head valve sheet" is an angle 45 degrees. If I am looking to buy a valve seat cutting tool is there anything else I need to know besides the angle when shopping for one? Has anyone here ever done this before and if so, what cutting tool did you buy?
Second question. The exhaust valves have a flat contact surface but the intake ones appear concave. Is this right or are the intake valves worn out? Hopefully the pictures will help make sense. (fyi, it is hard as heck to hold everything and take those pictures but hopefully they display my point)
Intake (notice the gap)
Exhaust (no gap)
Last question. I know it is important to measure the thickness of the mating surface where the valve contacts the head. The FSM has an entry for "Ex. In. valve" with the width listed as 1.0 ~ 1.5. Is that the spec I am looking for? If so, my valves are way off as it measures about 2.5.
And here is the head I am working with if anyone has anything else to point out that I should be looking out for.
I am in the middle of rebuilding the motor on my 1968 CL77. I am currently working on the valves and was hoping to validate a few things before I proceed.
First, I did the liquid test and found that all of my valves were leaking. Not too surprised as the bike sat for a long time and I had to do a lot of carbon and rust cleanup. After cleanup, I lightly lapped the valves and that seems to have stopped the exhaust ports from leaking but the intake valves are still allowing the liquid to bypass. At this point I want to get the seats redone and replace the valves if they need it. Although I know a machine shop that can perform this service I'd like to give it a try myself in hopes I can do the same on future rebuilds.
So first question. The FSM says the "Cylinder head valve sheet" is an angle 45 degrees. If I am looking to buy a valve seat cutting tool is there anything else I need to know besides the angle when shopping for one? Has anyone here ever done this before and if so, what cutting tool did you buy?
Second question. The exhaust valves have a flat contact surface but the intake ones appear concave. Is this right or are the intake valves worn out? Hopefully the pictures will help make sense. (fyi, it is hard as heck to hold everything and take those pictures but hopefully they display my point)
Intake (notice the gap)
Exhaust (no gap)
Last question. I know it is important to measure the thickness of the mating surface where the valve contacts the head. The FSM has an entry for "Ex. In. valve" with the width listed as 1.0 ~ 1.5. Is that the spec I am looking for? If so, my valves are way off as it measures about 2.5.
And here is the head I am working with if anyone has anything else to point out that I should be looking out for.