How to turn over an old engine safely

Okay, this post is in re: my post about engine work on my Honda CB350 M/C, where I was sold a used engine that I was told had pistons seized in the cylinders.

A little turning (180deg?) of the output shaft with a wrench revealed this to not be the case…turns just fine. My plan is to fill 'er up with clean oil, give a quick kick or five and check for compression.

However, this is an engine that seems to have been sitting for a LOONG time, as accessories were taken off one-by-one. I’m sure internal parts are close to bone-dry.

What would be the best way to prep this engine for motion? Thought I could spray a little penetrating oil through the plugs, the bottom of the cyl barrel, and on the cams, so that there’s at least SOME kind of lube present.

How do you-all handle an old engine that’s been sitting some time?

Sometimes an engine that seized up when hot will turn when cooled down. The condition of the pistons and cylinder walls isn’t known without visual inspection. Still why not see if it runs.

Shot some oil in each plug hole and fill the crankcase with clean oil. With the plugs out use the starting motor to turn over the motor. If the turns freely it won’t hurt the starter motor to crank it for a 1 or 2 mins. at a time. Don’t overheat the starting motor by cranking it too long without a “rest”. This should spread around the oil and lubricate the “dry” parts. If the bike is so old as to not have an electric start then you can do the same with leg power on the kick starter.

When you are ready install the plugs and see if you can get it to fire up. Don’t be surprised if it seizes up again once it warms up.

Locate an old time trigger oil can and squirt some light oil, Marvel Oil is good, into and onto every place you can…But remember, they TOLD you it was junk so don’t expect too much…

I agree about the Marvel oil. I squirted about 5cc’s into each cylinder of a Jaguar V12 that hadn’t run in a few years. After giving each cylinder a shot I rotated the enfine 360 degrees and gave each cylinder another 10 cc’s and fired it up.

While standing at the front of the car I couldn’t see the back of my garage for all the smoke. Got the neighbors’ attention too. Be prepared for a LOT of smoke.