De Gumming engines

If you know the provenance of an engine, then this method saves an awful lot of time.

This engine hasn't been run for 15 years and was siezed solid. couldn't move it at all. It had been removed, as was, from an old timer RC model, wrapped in a rag, placed in a drawer and "forgotten about".

The carb was a little rusty and the engine is covered in spots of hardened castor oil but it was obviously "gummed" up inside. The dired castor oil always resembles epoxy adhesive in this state.

I normally heat these up but this would ruin the gaskets around the "silencer".

So the easy way to try first is diesel fuel. The ether eats dried castor oil!

Firstly, completely slacken off the compression screw (or remove it!). Then flood with fuel - a bit of patience (which I don't have!) helps- to allow the fuel to penetrate.

Then wiggle and waggle the propeller until turn over can be achieved. Keep applying fuel and make sure the contra piston is free.

Keep this up until the propeller can be flicked.



Take care though - this is a diesel - even with the compression screw slackened off - it can still fire!

Also. when an engine - even when freed - is as stiff as this one. Don't use a new sharp propeller!



I hadn't realised until I'd gone to make a cuppa and saw all the red stuff all over the place!

I had managed to slice both my flicking fingers but the middle finger is quite deep. Not the first time - you think I would learn!