1975 cb in storage for 34 years seized motor

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Bowiesport

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1668 nw galveston bendoregon 97701
I everybody this is my first post and comment on this site. Hi for Bend Oregon land of lots of sunshine. I just bought ,last night,a beauty 1975 CB 750 for what I call cheap($790.00). It's in great shape and all there but the engine has seized FROM SITTING. Has anyone had any experience in soaking the cylinders with ????? and getting them to free up and still run??? Of course i am going to rebuild from scratch this winter but would like to see if it runs. Showing only 12k on the speedo and by the condition it was stored inside and dry. No rust in gas tank or fenders so low moisture content in the air. Any ideas???
 
I've read people spray PB Blaster through the plug holes and let it sit and soak for a while then slowly rock the
bike back and forth in gear.
There is a ton of info on many sites to accomplish this task.
I'm sure others will have better suggestions.
Compared to California prices you got a good deal.
Good luck, welcome.
 
Yup, what Daren said.
You can PB Blaster, WD-40, or any kind of penetrating oil. Then let it sit for a few days, lowly rock back and forth in gear. If id doesn't budge, wait a day and try again. Do it every day for a week or more.
 
Well we've got the engine out. custom built some motor mount for a v-8 style engine stand. tearing it down. wow some special tools needs… ok ordered up clutch socket and rotor removal tool…. lots of stuff.It helps when you have a full machine /welding shop at your disposal ….shot out to my buddy hans at creative welding…ok we've i mean me….have tried to break this engine free, but no luck. now that i am into it very rusty and carbon up pistons. may have broke a ring then sat for 24 years…sediment in the oil pan…..looks like a complete go thur and make new again….
 
Just for your information you dont need to remove the rotor unless you are going to replace it or have to work on the starter gear. People think you have to remove it but it is unnecessary...unless you want to buy the removal tool.
 
Fill the cylinders about half way with Coca-Cola Classic and let that soak for a day. No joke, the mild phosphoric acid eats away at deposits and the carbonation helps lift it away. Then empty them out and put in some automatic transmission fluid and let that soak for 2-3 days. Then get your favorite breaker bar (I used a 24" x 1/2" Snap-On) and a high quality socket and try to turn the crankshaft via the nut on the left side. Use a bouncing motion not a slow build up of pressure. Repeat as necessary. After it's finally free use a lighter oil like WD-40 to wash out the cylinders, several times.

I did this to the bike pictured in my profile (and I've used this same method on several car engines) as it was also seized from sitting out in the weather. (Actually, it was buried in snow in Mi.) Afterwords I cleaned out the tank by sloshing solvent around in it and emptying that out by hand and replaced all the jets while rebuilding the carbs and it's ran fine ever since.
 
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