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Discussion Starter · #1 · (Edited)
1971 CL175.

We finally removed the engine and opened it up ..... we found a damaged CAM. The damage (we believe) came from the lack of oil. We discovered the spring loaded valve on the oil filter cover was not moving (stuck) so it blocked the oil from circulating to the head. It was dry as a bone when we opened it up. So .... a new cam, rocker arms, oil filter cover, pistons and rings were ordered. The head was sent out for machining.

The damage to the CAM made it impossible to set the points/ electronic ignition.

With everything cleaned up and the new parts in, the engine has been reassembled and ready to go. More to follow ...........

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Sky,

I had a similar experience with a 1970 CL175. Bought it with a frozen engine. Upon inspection, the camshaft was snapped. A shade tree mechanic had opened the tach drive, probably to seal an oil leak, and gooped it all up with silicon sealer. Well, it stopped the leak alright, along with oil flow to the cam journal. Cam bearing froze, breaking the shaft. Pistons were OK, rings were replaced, head was OK. Bought a used head with cam off E-bay....all back together and operational.

Silicon does NOT belong in a motorcycle engine!

Michael

1968 CL175
1966 CB77
1972 CT90
 

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There are plenty of ways to restrict or thin the oil running to the head it's an issue with all the 175' and 200 twin's
They all end with melted journals and trashed cams
Did you check the oil pump plunger is within spec, that holes in the case between the two outer rear cylinder studs are clear, and the cam journal gaskets are the correct way around and not blocking the oil passages between the journals and the head
You can confirm oil is getting to the head by filling with oil loosening the two rear studs and kicking the kick starter vigorously ( it takes forever but less time than finding a new cam) also remove the front rocker covers and confirm oils getting there as well
 

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Sensei
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Just FYI........

This type of camshaft and bearing journal damage is also typical of what happens when the oil in the engine becomes fuel-thinned......

At least weekly check oil level and smell the dipstick for gasoline odor......
 

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Discussion Starter · #6 ·
Thanks guys. I didn't realize there were so many ways to mess up the top end. I will keep an eye on everything that's been suggested.

We got the engine running today ..... just a short time to make sure everything was ok. There is definitely oil coming out of the two rear studs so we know we have oil in the head and on the cam. Yippie!!!!

Tomorrow we are going to re-check the valves and timing (electronic ignition) to make sure everything is still set correctly. After that its time for a test ride and a break in. I bought this bike not running so Im excited to see how it runs and rides.

Thanks for all the input. Video to follow.
 

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To add to Steve's thin oil.
Make sure you switch the gas off at the petcock every time you stop the engine, the float valves generally leak a little and with the engine off and the petcock open ( especially when on the side stand) fuel can full the carb bowls and run through the manifolds to the head and down through the cylinders past the rings and into the crank case ( and thin the oil)
 

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Discussion Starter · #8 ·
To add to Steve's thin oil.
Make sure you switch the gas off at the petcock every time you stop the engine, the float valves generally leak a little and with the engine off and the petcock open ( especially when on the side stand) fuel can full the carb bowls and run through the manifolds to the head and down through the cylinders past the rings and into the crank case ( and thin the oil)
I can see all that happening with the short side stand because the bike really leans over when parked. I use the center stand most of the time.

In regards to the petcock .... just about every carbureted bike I have needs to have the fuel shut off. Most of the time I shut it off a block or two from the house just to drain the bowl.
 
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