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Engine basics => Engine set up tips => Topic started by: peabody on January 26, 2017, 08:00:44 AM
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So I bought an unflown RC plane, with all the crap and a LA 46 installed.
The engine is stuck tight....so far I have put after run oil down the carb, into the exhaust port and down the glow plug hole....no action.
Someone suggested blasting it with a heat gun....but it seems to me that that is why it is stuck....garage temps hereabouts get to 150* or so..
Thoughts?
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Pull the engine off the plane and soak it in a coffee can with fuel for a couple days. The alcohol should loosen it up.
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Heat should help, Rich. I would try that first, or maybe what DB suggested, or maybe even both.
I had a 20 year old engine that I didn't take care of, and it was solid, and the heat worked great to loosen it up. It runs great now.
Good luck!
R,
Chris
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So I bought an unflown RC plane, with all the crap and a LA 46 installed.
The engine is stuck tight....so far I have put after run oil down the carb, into the exhaust port and down the glow plug hole....no action.
Someone suggested blasting it with a heat gun....but it seems to me that that is why it is stuck....garage temps hereabouts get to 150* or so..
Thoughts?
It got stuck because it heated up, then cooled down.
Don't heat it with a propane torch, as long as you have an oven with a thermostat. Remove the ancillary parts, put light machine oil in all the holes, and put it in the oven at about 225-250 for about 1/2 hour, pull it out with oven mitt, attach prop, then flip it around until it's nice and flippy. If no luck, try at increasing temperature. The only way it won't work is if it is severely rusted, otherwise, the old gummy oil with thin out and once you get it moving it will be OK.
Brett
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Long days at 150 degrees will oxidize the oil, turning it into varnish. This is bad. Getting it good and hot will soften the varnish so you can get it off. This is good.
If you take Motorman's advise and get it up to 350 degrees, just don't forget and leave it that way for a week, and you should be fine. I like Brett's suggestion much better -- if I were going to do it in my shop with heat, I'd use a Monocoat gun.
Personally, I use whatever straight alcohol I have at hand -- usually isopropyl or denatured. But I'm careful to remember that I've used it, and that it attracts water like a bandit. I'm of the opinion that if it's that hard to loosen it's time to take it apart and crock-pot the pieces.
Whatever else you do, make sure you're getting solvent (alcohol, fuel, or Brett's light oil) into the upper cylinder, either through the exhaust ports or down the glow plug hole.
Consider crock-potting the thing if it's really that bad.
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Just a caution, if it does have rust and you prop it and turn it over until it gets flippy you can do some serious damage , you can do what Brett suggested or use a monocote heat gun , and very important I would remove the backplate , look inside to see if its rusted or what is there. and if you see it really hard gummed or rusted then spray it out with a can of carb cleaner. if it is rusted do no turn it over, put it in a crock pot with antifreeze, or a gallon can of Berrymans carb cleaner. take it apart after an clean it all, reinstall parts then test the engine
Randy
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It got stuck because it heated up, then cooled down.
Don't heat it with a propane torch, as long as you have an oven with a thermostat. Remove the ancillary parts, put light machine oil in all the holes, and put it in the oven at about 225-250 for about 1/2 hour, pull it out with oven mitt, attach prop, then flip it around until it's nice and flippy. If no luck, try at increasing temperature. The only way it won't work is if it is severely rusted, otherwise, the old gummy oil with thin out and once you get it moving it will be OK.
Brett
This is the best ticket here me thinks. I've sold hundreds and hundreds of engines on eBay over the past 15+ years, many of which needed "reclaiming". And I processed many engines 15+ years before starting eBay.
The explanation: the crankcase will generally expand with heat much more significantly than the innards. And the oven provides the best source of even heat.
I generally start at 325 to 350 degrees. Many "stuck" engines free up pretty quickly in that scenario.
Just remember to clear off anything highly flammable, and stay near the oven.
Good luck!
Dennis
Edited to add: I always remove head, backplate, carb or needle assembly, etc. before heating. The objective is almost always to free up the moving parts!
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Just a caution, if it does have rust and you prop it and turn it over until it gets flippy you can do some serious damage , you can do what Brett suggested or use a monocote heat gun , and very important I would remove the backplate , look inside to see if its rusted or what is there. and if you see it really hard gummed or rusted then spray it out with a can of carb cleaner. if it is rusted do no turn it over, put it in a crock pot with antifreeze, or a gallon can of Berrymans carb cleaner. take it apart after an clean it all, reinstall parts then test the engine
Randy
Well said Randy, rust changes the game. Personally, I haven't had much success with badly rusted parts.
Dennis
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Thanks....
I'll try the monocoat gun first.....primarily because Edith would kill me if I cooked a motor in the new oven....
I'll report
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Thanks....
I'll try the monocoat gun first.....primarily because Edith would kill me if I cooked a motor in the new oven....
I'll report
Oh, that's to bad! ??? (So Edith is the boss eh?) LL~ LL~ LL~
I put them in the over (On an OLD cookie tray) at 300
for 15 min. or so and when I start smelling castor oil it's time to take them out.
On BB engines, the rear BB usually drops out when hot.
Jerry
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Boil It . two or three times. CRC between . Water in a pot , for awhile .
Darn Stuck engines like to hold on for two weeks before they free off .
so you CAN boil it a half dozen times . Maybe its the heat cycle thing ? .
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150 is not enough. Hold a mounting lug with vise grips and evenly heat with propane torch until slightly smoking which is about 350. Then try to prop it over.
MM
150 C equates to just over 300 F, so it could be valid.
I use 50% ATF 50 % acetone as a penetrating oil but it will only 'penetrate' if there are micro cracks and fissures it can get into - hence the use of heat as an adjunct or vibration like ultrasonics.