I recently purchased a package of used planes from a man. One of the planes was a .60 Piper Cub. When i first looked at it the prop was stiff but it was moveable, brought everything home and started working on loosening them up and now it seems to have only gotten stiffer. I have removed the glow plug and sprayed the system with wd-40 but still no luck. What do you all suggest i try next?

Learned from and older gentleman, take the engine apart as much as you can without breaking bolts-screws. Put engine in a pan of water with Dawn Dish liquid, just a few drops, bring to boil. Unbelievable how it will loosen all the parts and clean it up. Don't leave it boiling cause you will have bubbles all over the stove which makes MAMA very unhappy.

There's other things you can do like but fuel in the engine, warm it up with the Monokote gun etc

I use diesel fuel because it will disolve rust, keep in mind that diesel eats rust but also rubber seals. First remove the glow plug and carb. Then get a metal container large enough to fully submerge the engine in the diesel fuel. let it sit for a day or two. then flush the engine with fuel, now add air tool oil or after run to the cylinder and carb opening(intake throat). try to turn it over, if it won't turn put a prop on it and VERY gentley try to turn the prop side to side. As it breaks loose flood it with oil and turn it over slowly for a couple mins. I've used this on 2 engines seized from years of storage, one I resealed after, The other ran fine without any work. good luck

I've read a-lot of threads here where many members recommend a good soaking in methanol fuel to loosen up old congealed castor oil. I would guess denatured alcohol would be effective also. Lacquer thinner would do it but you risk ruining any rubber or silicone sealing gaskets.

Bill

I learned here some time ago where some guys swear by a product called Dawn Power Dissolver.

Bill

I used some Liquid Wrench to unseize an old Enya engine. It's a very thin, penetrating oil, made to help loosen up rusted/seized bolts.

For years I have used boiling in water with any kind of mild surfactant and normally use dishwasher power. This is primarily for cosmetic cleaning. However the very best initial approach in the case of an engine that is stiff but still can be turned a bit with a prop mounted is simply soaking in glow fuel old, new whatever. This is the reason you should never discard any old contaminated fuel that does not run well anymore, away.


In an extreme cases heat can be the answer and this can be done by boiling or very careful use of a heat source with a prop mounted and gentle rocking of the prop while hot.

Take a covering heat gun and heat the engine up real hot then just turn the prop. If you don't have a heat gun the the kitchen oven will work too. Castor oil gums up after time and the heat will soften it up. I then break down the engine and clean it up using a tub of boiling water and rags then use after run or Marvel Mystery Oil and reassemble the engine. If you have a lot of engines that need cleaning up then I use an {OLD} crock pot and anti freeze to clean them up. Not worth the time or trouble for only a couple of engines though.

If it's rusted tight you'll need propane gas.

Bill

If it's really rusted then the CP and anti freeze will work most of the time. Depending on the engine sometimes pulling the prop and tossing the engine is a better choice. It sounded like just hardened Caster Oil so heat should break it loose.

Good advice, thanks. I freed up a badly rusted Enya .19 I bought at an auction and used a propane torch and some gentle persuasion with a peice of hardwood dowel and a hammer to break the bond between the cast iron piston and steel cylinder. I was lucky, no new parts and it cleaned up fine.

Bill

If it's caster locked I highly recommend the Glycol based antifreeze in a crock pot method..
Lots of threads here on that..

I did mine in a crockpot I'd clearly marked NOT FOOD SAFE with a giant magnum marker..
Set the pot to low.. disassemble the motor as much as possible.. tie all the bits together with a wire fishing lead or thin gauge music wire and drop it in the bath.
Check it at 4 hours. See how it feels drop it back in if it needs more.. Dry it out with compressed air lube with ATF.

I've done 5 motors that were locked up from 15 years in storage.. They all came out fine and run great.

I've been rebuilding some old K & B engines this year, and I've been tearing them down to lots of small bits, cleaning with rubbing alcohol, and a small piece of scotch brite. So far I've got 3 freed up, and 2 have been bench run. Boy are they noisy suckers. I'm putting one in an old quickee 500 fuselage, for a fast fun flyer. Daren

I was out last week looking for something in my garage and came across a bag of old engines I had way back when. I pulled out my old VECO .19 I used for U-Contro and free flight, even an old McCoy .19, everything in that bag rolled free and clear. I must have cleaned them up before I put them away. I haven't seen these engines sense 1977 or 78? I bought them in or around 1960 or 61. I usually clean engines going into storage and leave them dry, no oil or anything after an alcohol flush. I lived in Calif. so there wasn't a lot in the way of moisture so there was no rust at all in these engines. Even my old .049s were OK.

You should live in the East. It is humidity city around here