Engine gummed up ? Put it in oven ?
 

Ran it & flew plane a couple of yrs ago then put it in the attic. Guess I neglected to put after run oil in it. It is on old OS 40 FP. Remember reading about putting engine in oven to free it up. Put it in oven at about
210 for an hour, no luck. Should I get it hotter? Remove plastic throttle Arm?

Yes, do both.

Heat it up to get it so you can get it to turn then immerse it in methanol or glow fuel. Every so often stick a prop on it and work the crank back and forth. The heat will loosen it up but once the sticky oil goo cools it will solidify and make things tough to turn over. The last gummed up carburetor I had to free up needed a soak in methanol to free up and stay free. Heat worked as long as the carb was warm, adding oil didn't help. Just my worthless opinion.

What temp do I put oven ?

As low as is necessary. 300F-350F isn't unreasonable. Just remove plastic parts that might melt like the throttle arm.

When I change bearings I start at 300F and go up from there. I doubt you'd need to be hotter than that to free up a stuck engine.

Hey thanks - 300 did it. Turning over now !

Now keep that engine lubed up & don't let them set long without cranking them over to see if they need lubed again..........

Wait for it to cool off first. Not sure if the oven trick works if it is thick carbon or varnish. The soaking in fuel will work for that but you might have to let is soak for days. You can also soak in pure methanol but may cause the aluminum parts to corrode.

My comment was based on the assumption the engine was cooled.

I would use a light oil once it's turning over instead of fuel.

Gummed up?
 

I usually put mine on the grill. Gives it that smoky smell. doesn't piss the wife off as much either!Max

There is also the antifreeze method..............http://www.rcuniverse.com/forum/begi...eze-crock.html

What PERSONALLY works for me, is to load it up or soak it in Marvel Mystere Oil. Also use Marvel as an after engine run lubricant. Have had no problems with any kind of engine in years now, using Marvel.

You would have to let is soak a long time in MMO. It does very little to disolve castor oil. Perhaps the small amount left from an engine run mostly with synthetic oil, but for any engine using all castor oil or 30% or more castor oil it does little to degum an engine.

I too use Marvel Mystery oil for years, just forgot to when I chunked this one in attic for a couple of years. 300 in the oven for about 30 mins did the trick. Once cooled put the old
M M Oil in it. Tank was all full of crud (put it away with fuel in tank-duhh) Replaced tank and it fired right up yesterday !

Not always true. I've had glow fuel free up gummed castor in an hour or so. Either way, it's the safest and easiest way to free up an engine like that. Once the glow fuel has freed up the engine either run it or flush it to get the glow fuel out. Alcohol works to flush things out.