rszanti

I have an OSFL-70 thar's been sitting for a few years. It won't turn over. I'm sure this has been covered somewhere but I can't find it. How do you loosen one of these engines up ?

I did try warming it up with a heat gun but it didn't help.

jaka54

You have to take the engine apart,which is very easy to do!

Jesse Open

Heat alone is nowhere as useful as heat and penetrating oil combined. Not just "warm' HOT!
It may take several applications and you may need more than gentle force.
Once moving, you can dismantle and clean up as needed.

jaka54

Heat and oil is not going to fix it! The problem is the gummed up ball bearings and they have to be replaced...which is very easy to do.

Jesse Open

LOL! Relax and read again.
Where did I say that heat and oil would "fix it"? I said both were very helpful in restoring movement.
Taking apart generally requires getting the frozen, gummed up parts to move and very often, getting moving in the cylinder etc Next, comes cleaning. At that point one can evaluate condition of all and decide what to replace.

You have no way to know from what the OP said that the bearings are the frozen parts or the only frozen parts.

jaka54

If a glow engine is stuck and cannot be turned over it is 99% certain that the ball bearings are full of old gummed up orange castor oil.

Jesse Open

Naw, experience says that's not even close. Just as likely a stuck piston or a combination of stuck components.
This isn't a two stroke engine. It has many parts not present in a two stroke.
Get over it, in order to take the engine apart, one should first get movlng parts moving.

99% bearings only?


Don't be ridiculous. Why be a hack?

mgnostic

It's messy and it's a bit of a hassle but it will work. Disassemble the engine as far as you reasonably can, such as removing the head and any of the covers and the backplate. Get a thrift store crockpot and some cheap green antifreeze. Fill the crockpot with enough antifreeze to cover the engine. Submerge the parts and set the crockpopt on high and leave it over night. After sitting in the hot antifreeze overnight you should be able to take the engine out using tongs or a pair of pliers. While it is still hot enough that you need gloves to handle it you should be able to bolt on an old prop or a piece of scrap wood and gently but firmly turn the engine until the crank spins. It may take more than one treatment to get things loosened up and still more to really clean it up. . Be prepared to remove the valves as they are likely gummed up as well. It is likely that you will have to scrub a bit to get the old congealed oil off the engine. I like to use a small brass brush from HF but even a toothbrush will work while the varnish is hot and soft. Once the engine spins freely you are probably still going to have to remove the crank to thouroughly clean the bearings and the snout of the crankcase. My personal experience is that saving the bearings is about a 50/50 chance. If they are just gummy then clean them and run. If they are rusty or crunchy even after cleaning then replacement is the way to go. If you can source OS bearings, I've had good luck with Boca Bearing. BTW, the crockpot is now useless for anything but parts cleaning so don't use your wife's favorite appliance.