Jam in motor

[westree]

Hi Everyone,
New member and new 1965 CB77 owner. I am going through a rebuild(which I will document in the next few days) but I have hit a major stop. Yesterday while I was setting my timing I was turning the motor with the crank bolt. The motor had been cranking fine for the last week with the electric start and kick start. This time I turned the motor over and I heard a few clicks then the it came to a complete stop. I could back it up about 2 rotations and then it locks up again. I can turn it back and forth about 2 rotations but it always locks up at the same place. The starter motor is not the problem as it does it when the starter is disengaged. The kick start gears are find as it does the same thing with the gears removed.

Any ideas?

Thanks

[G3]

Hi New Member
And welcome to the forum.
Just a few thoughts; Did you rebuild the top end? Are the plugs out while you're turning the crankshaft? Does the cam turn when you turn the crank bolt? Just trying to determine if there's an issue with the chain. Remove the cam chain tensioner assy and peek inside. Should be able to see the chain with a flashlight.
Be sure to post your location.

[LOUD MOUSE]

Do you have the right side cover (KS cover) installed.
If you do did you turn the KS shaft clockwise to stop and then make sure the spring is installed ina way to keep the KS shaft to stop?. ..........lm

Hi Everyone,
New member and new 1965 CB77 owner. I am going through a rebuild(which I will document in the next few days) but I have hit a major stop. Yesterday while I was setting my timing I was turning the motor with the crank bolt. The motor had been cranking fine for the last week with the electric start and kick start. This time I turned the motor over and I heard a few clicks then the it came to a complete stop. I could back it up about 2 rotations and then it locks up again. I can turn it back and forth about 2 rotations but it always locks up at the same place. The starter motor is not the problem as it does it when the starter is disengaged. The kick start gears are find as it does the same thing with the gears removed.

Any ideas?

Thanks

[westree]

Thanks guys,
I took the top end apart and found a few interesting things. One was a small screw head lodged In the right piston. Remarkably only minimal damage to the piston and no damage to the valves. Lucky! No sign of the rest of the screw, which scares me a little. Secondly I found that the cam chain timing was way off. All reset and back together. Hoping to hear her purr this weekend!!

[DianneB]

I would be VERY concerned about where that screw came from and how it got into the cylinder! If that had happened while the engine was running you could have done MAJOR damage or destroyed the engine.