1966 CB77 Restoration Project

[jkv357]

I made up a frame of landscape timbers to support and hold the top crankcase and cylinders and tried once again to free the pistons with a 4 lb. sledge hammer and blocks of wood. No movement at all of the pistons or crankshaft. I'm just splintering wood. I'm thinking a piece of pipe might be required to replace the wooden blocks. But I'm also wondering if it's more than stuck pistons.

Have you tried adding some heat?

It's amazing what thermal expansion can do. I recently had a socket-head cap screw that was tight enough that it eventually stripped when trying to remove it. Wouldn't even budge a little. I had heated the entire piece to 400F loosen any loctite, but it didn't help.

After drilling off the head and separating the pieces I mounted it in a vise and heated the area around it. I had a pipe wrench on the broken screw (there was plenty sticking up) and was ready to really crank on it. After heating for a couple minutes I put the wrench on it and before I was even able to put any pressure on it it turned. Could have spun it out by hand.

[Seadog]

Thanks Rusty and jkv for your thoughts and ideas. First thing this morning, I went to the hardware store and bought a 1.5" x 12" iron pipe nipple and a cap. The helpful hardware man cut the thread off one end of the nipple for me. When I got home I attached the cap, fetched my 4 lb. maul and was able to drive both pistons out of their sleeves. Hallelujah.

I found that the rods were not stuck to the crankshaft, but the right piston pin is stuck in the piston. I've applied PB Blaster to it and have managed to get it to move a bit. I'll work on it more later. I've managed to get only one pin clip out. I imagine I'll have to drive both pins out somehow. Image from Imgur because I still can't post directly.

[G-Man]

Nice job!

G

Thanks Rusty and jkv for your thoughts and ideas. First thing this morning, I went to the hardware store and bought a 1.5" x 12" iron pipe nipple and a cap. The helpful hardware man cut the thread off one end of the nipple for me. When I got home I attached the cap, fetched my 4 lb. maul and was able to drive both pistons out of their sleeves. Hallelujah.

I found that the rods were not stuck to the crankshaft, but the right piston pin is stuck in the piston. I've applied PB Blaster to it and have managed to get it to move a bit. I'll work on it more later. I've managed to get only one pin clip out. I imagine I'll have to drive both pins out somehow. Image from Imgur because I still can't post directly.

[LOUD MOUSE]

Now that's a real man's hammer for sure. ...............lm

Thanks Rusty and jkv for your thoughts and ideas. First thing this morning, I went to the hardware store and bought a 1.5" x 12" iron pipe nipple and a cap. The helpful hardware man cut the thread off one end of the nipple for me. When I got home I attached the cap, fetched my 4 lb. maul and was able to drive both pistons out of their sleeves. Hallelujah.

I found that the rods were not stuck to the crankshaft, but the right piston pin is stuck in the piston. I've applied PB Blaster to it and have managed to get it to move a bit. I'll work on it more later. I've managed to get only one pin clip out. I imagine I'll have to drive both pins out somehow. Image from Imgur because I still can't post directly.

[Seadog]

Thanks, G and LM. I'm glad that battle is won, but the war rages on. I managed to remove the 4 pin clips - they're ruined, of course - but those pins just wouldn't budge. I ended up cutting the pistons off with a hacksaw. Up one side, across the top and down the other side. On the left side piston I prized the halves apart with two screwdrivers. It actually broke the piston casting where the pin went through and it all came apart. The pin then slid out of the rod end. It was just seized in the piston. The right side was more difficult. Again, I cut the piston in half. One half fell off the pin, but the other half was stuck on the pin. I heated it a bit and it too fell off. Now, however, the pin is stuck in the rod. It won't budge. I've tried heating up just the end of the rod a bit and turning the pin with vice grip pliers, but the pliers just spin on the pin. I've stopped for the day after just soaking the rod end in PB Blaster. I'll take up the fight again tomorrow.

[LOUD MOUSE]

I use a brass tube just big enough to fit over the pin and contact the rod end and middle then use a brass hammer and Tap And Tap And Tap until the pin comes out. ....................lm

Thanks, G and LM. I'm glad that battle is won, but the war rages on. I managed to remove the 4 pin clips - they're ruined, of course - but those pins just wouldn't budge. I ended up cutting the pistons off with a hacksaw. Up one side, across the top and down the other side. On the left side piston I prized the halves apart with two screwdrivers. It actually broke the piston casting where the pin went through and it all came apart. The pin then slid out of the rod end. It was just seized in the piston. The right side was more difficult. Again, I cut the piston in half. One half fell off the pin, but the other half was stuck on the pin. I heated it a bit and it too fell off. Now, however, the pin is stuck in the rod. It won't budge. I've tried heating up just the end of the rod a bit and turning the pin with vice grip pliers, but the pliers just spin on the pin. I've stopped for the day after just soaking the rod end in PB Blaster. I'll take up the fight again tomorrow.

[Seadog]

Thanks, LM. That's a good idea. Before I saw your post, I sat for awhile thinking about it and came up with a slightly different method. I just treated the pin like a bushing. I have ¼" rod, washers, nuts and I cut a piece of conduit I had lying around and simply pushed the pin out. I lubed it as it moved and it gave no resistance. On the last bit, I attached a vice-grip and lightly tapped it with a hammer to completely remove the pin. Job done.

I'm not sure about what's next. I have to decide what I'm going to do about the top crankcase - replace it or try to repair it. There are pros and cons for both options. The same for the head. I broke fins dropping it. I have to decide whether I want to try an aluminum braze repair or just replace it. I just don't think that I can get it hot enough for a successful brazing repair, but then I can't seem to find a good replacement. More for me to think about. Until I make a decision, I can be cleaning, fixing and/or ordering parts.