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[nitro gas]

I am new to diesel engine this is my first

I brought a boat that came with a FROG Diesel engine
My intensions are to sell it on so i desided to clean it, before i dismantled it, it tured over great with good compression.

Right

Now i have cleaned the engine put it back together and applied after run oil to lubrcat it.
I fitted back together and it wouldnt turn over and lock's up.

So i cleaned it again and removed the oil, put back together it still wont turn over it locks up.

I have tried pushing the piston up into the liner free hand and the compressing, is stopping it from going all the way up.
It still wont turn over it gets stuck and locks up.

I have dismantled it 4 times since and dont have a clue why its locking up.

Any ideas or am i doing something wrong

Some pictures may be poor

[bogstandard]

The shot on the second to last picture shows the cylinder, inside the cylinder is what is called a contra piston. It slides up and down inside the cylinder, and is adjusted up and down by the screw in the top of the cylinder head coupled with compression from the piston, to increase/decrease the compression ratio.
Start off with the screw out of the cylinder head, your conta piston just might be stuck. DO NOT try to remove it, if you have to free it off slightly, just put a little paraffin in the bore and a wooden dowel is tapped against it gently with a hammer so that it moves towards the cylinder head. This will move it out of the way of the piston and it should then turn over. Then just put the screw into the cylinder head and tighten it until it touches the contra piston. Leave it like that, the person who buys it should then be able to adjust it correctly until it runs.

Hope this helps

John

[grasshopper]

With it being a diesel engine, did it have a contra piston in the liner?

With diesel engines that I remember, there was a T bar which was a screw mounted through the top of the engine's cylinder head that screwed in a piston above the one connected to the con-rod - is this free or has it got jammed in the bore and locking it up?

[nitro gas]

Thank for the help

Its now fixed
All i did was added more lubrication to the piston & lining

Sorted

Thank you

[andrewh]

Nitro gas

Glad to hear it is fixed - its a nice little engine - very freindly, flexible and long-lived (it also runs backward with no physical changes, like a cox reed-valve )

Its a Forg 1.49 CC Vibramatic, and the usual problem (easily fixed) is that the reed valve goos up with time and castor residue - soak in cellulose thinners and blow into intake to free it!

andrew