Randy,

  I have two new Magnum .36 xls engines. They have been on the shelf in their boxes wrapped in original plastic bag for over ten years. Yesterday I pulled them out and they will not turn over. I do not want to scar the piston or sleeve by forcing it. How should I proceed?

Keith

Randy's advice should get it loosened up, but it's probably not from rust or coagulated oil. I checked otherwise unopened Magnum 36s, and both where shipped with the piston at TDC. Heat alone should work. Once I got mine off of TDC and put a glow plug in it, everything was fine and the oil looked fine.

     Brett

I have setup over 100s  of these,  and  I have seen them as Brett  described, set on TDC, I have also seen them  with hard dried oil, and  I have had them here on TDC with nearly zero oil in them, So I would still suggest  looking into the backplate area, it easy to do, and will not hurt anything, The rear gasket is  plastic  and  clear, and normally  will not  tear, at least I have not torn one  yet

Randy

Thanks everyone. When I put them in the oven am I just warming them up at 150 degrees for an hour or two? Or do I full blast them at 550 for an hour or two?

Thanks everyone. When I put them in the oven am I just warming them up at 150 degrees for an hour or two? Or do I full blast them at 550 for an hour or two?

DO NOT  put them in the  oven, heat the top of the case  and  head  with a  monocoat  heat gun  or  hot  hair dryer, you can do too much damage in the oven, and that is not needed, juts  use the  gun for 10 or 15 seconds
You want to get the  outside of the head and  case  hot  without  getting  the piston hot, so  it does not take but  10 or so seconds

Randy

Thanks.

Thanks everyone. When I put them in the oven am I just warming them up at 150 degrees for an hour or two? Or do I full blast them at 550 for an hour or two?

   150 is safe enough, your car gets that hot on a summer day. 550 will certainly destroy something! But you probably just need a heat gun for less than a minute, as Randy says.

    Brett

If you remove the backplate, you would be able to see if the piston is  at TDC, or  it maybe off slightly on way or the  other, you would turn the prop that way if, it is on one side or the other at TDC

You can damage, the bearing seal, gaskets, or maybe other things at  550 degrees in an oven, is why I posted that, plus some other things that you do not want can happen, and "IF" you have dried oil, that can make it worse

When the glow plug out and the back plate off, it is very easy to see the inside, oil the engine, and clean anything out that you do not want in it, also the already mentioned rod check to see exactly where the piston is, and removing these parts is very easy and simple

The reason you want to heat a cold engine up quickly with a heat gun, is so the outside case/sleeve , gets hot and expands away from the  piston,  If you heat it slowly in an oven, it will heat the piston and the piston will grow to match the  sleeve, ie.. not getting it loose, also  when you pull  it out of the oven, then sleeve/case starts cooling faster than the piston, and will actually get  tighter on the piston.

Randy

I think people are overthinking the engine stuck thing.   Just stick a prop on it and pull it off tdc.  Maybe pull off the backplate so you can oil the rear bearing . The only new motors that have passed through my hands that  really need complete disassembly are fox motors that were run at the factory with castor oil and have been sitting around for a few years.

   With ABC/AAC  engines, you sometimes have to absolutely hammer on the prop to force it loose, or put far more torque on it than you would want. It's not coagulated oil, it's cold-welding or something very like it. Heat it up, the cylinder expands, and you can move it. In the case of both of my engines, it felt completely locked, I heated it up a little, and it moved easily and was very free.

     Brett