1974 CL200 seized. Help

[LiveStoked]

I just bought this CL200, in damn near mint condition. The motor is locked up, but I know for a fact it isn't majorly locked up, just needs a little persuading to come unlocked. I've tried putting it in gear and rolling it back and forth after letting PB blast sit in the cylinders for two weeks. It did nothing but make the back tire skid. Now I'm trying to turn the crankshaft, but my question is, how do I turn the crankshaft without disassembling the whole motor? Do I take off the clutch side panel off, or the panel where the alternator/generator is?

Any help is appreciated. Thanks!

Also, title was lost by 4 owners ago, so any recommendations to get it on the road would be great. I think Vermont can help?

 

[Tim]

Seems to me if you can't get it to rotate using the rear wheel, then trying at the crank isn't going to work either. Forcing it loose is just going to guarantee needing to tear the top end down anyhow.

I haven't used it myself, but everyone with a seized engine I've seen use Marvel Mystery Oil to try and get things moving.

 

[teazer]

Heat and your favorite rust dissolver are the only tools that work - over time.

 

[focusinprogress]

I was able to free a cb360 motor that was locked up for almost a decade by filling the cylinders with Automatic Transmission Fluid and letting it sit about a week....then tried standing on the kick lever and give it a little bounce....when it didn't budge I left it alone another week and tried again....little bounce gave me a nudge on the lever, so I gave it a bigger bounce and she freed right up. this was just a few months ago, bike ended up with 120psi compression cold and ran great after a tune up

 

[1sttimer]

1974 CL200 seized. Help

Try some marvel mystery oil in the cylinders.

Edit: I just read the bottom of Tims post

 

[Redliner]

Mystery oil is just mineral spirits, mineral oil and perfume. I've had better luck with ATF mixed with just a bit of acetone to thin it. It will stick and emulsify longer so you have to top it up much less.

If you put anything in the cylinder, do so BEFORE you change the oil. Oh, by the way, change the oil!

Just let the trans fluid work for a week or two and be sure to top it up until things break free. Once it's spinning, just do a compression reading and all should be fine.

Don't force it. If you can't spin it with a regular kick on the start lever and rocking in gear, let sit longer.

 

[Brodie]

Heat and your favorite rust dissolver are the only tools that work - over time.

Teazer is right.

I had the same problem with my GS, I tried everything. Acetone/ATF mix, Kerosene, Turps, Diesel. None of it worked. I then tried belting it with a BFH and a block of soft wood on the piston. That didn't work either.

In the end I bought a plastic ended hammer and a propane torch. I heated the cylinder and the hit the piston gentle with the plastic hammer. It took about 8 heat cycles but between hitting the piston down and pushing it up I got it free.

Best thing for it is a rust dissolver bath for a week minimum. Then clear all of that out and use a propane torch to expand the cylinder, when it is hot gently "prompt" it with a plastic hammer. After it has cooled either heat it again or refill the cylinder with kero/turps/atf/mystery oil/whateverticklesyourfancy. Just do that a few times and you will be golden.