Head Removal 2QM20 Diesel

[Marktjski1]

I just bought a money hole in the ocean. Anyone know a trick to removing the head on a Yanmar 2QM20. I have no idea the last time this engine ran but it is in pretty rough shape. I have added penetrating oil and I'm going to let it set over night.. Wish me luck.

Thank You..

[Sailorman Ed]

Depending on how rusty the bolts are, you may want to soak there repeatedly for several days before even starting.
Take a picture before you start removing wires and hoses.

[Marktjski1]

Thanks Ed.. I have the bolts off already. I don't want to ruin the head trying to pry it loose. Was hoping someone knew a trick to separating the head from the block..

[Cheechako]

Watch for hidden bolts.... seems like my 3GM30 had some that weren't apparent...?

[Marktjski1]

Thanks Cheech.. I have removed six.. and everything else that was attached to the head.. I'm thinking a block of wood and a BFH (Big Friggen Hammer) might do the trick dislodging it..

[donradcliffe]

Try cranking the engine.

[Cheechako]

Also, I cant remember if there are dowel pins.... so for it up ...not sideways!

[Bill Seal]

Take it from an old hotrodder, do NOT try driving a screwdriver between the head and block.

[Reefmagnet]

I've owned a couple of "Thor" brand hammers with copper head on one side and a leather head on the other that have proved invaluable over the years for completing tasks such as yours.

[tdh1849]

Just a thought but call, " Complete Yacht Service" Yanmar dealer in Ft.Lauderdale, ask for the owner Mark, (USMC), tell him Pat N, now in Tampa told you to call.
He knows everything there is to know about Yanmar or Perkins engines.

[1HappySailor]

Check out and exploded assembly view....may be helpful.

Jim

http://boatdiesel.com/Engines/Yanmar...=3966618313993

[Madehn]

1) crank the engine if you can
2) buy one of the big orange plastic "dead blow" hammers from harbor freight and hit it from the side- try some firm taps all along the side- repeat as necessary- dont be in a hurry.

These hammers are hollow and filled with sand- they dont mar surfaces, spread the force out, and the sand following up on the inertia of the hammer keeps it from bouncing off-- they are great to have in the tool box-- you dont need it often but really handy when you do.

[Wotname]

If you really need to get serious yet avoid damage, try this.

turn the engine over until one cylinder is at TDC on a compression stroke, remove injector, pack the chamber with grease, refit a custom made "injector" to which you can attach an air hose to, connect this up to a air compressor and wait for the head to be lifted off by the air pressure.

You will have to lock the flywhell in place so the piston remains at TDC.

Depending on how struck it is, this may hours to months but it ALWAYS come apart without damage.

I have seen this work on engines with rusted in pistons, rusted on heads etc.

[shakey doug]

Your #5 post has the answer, you may have to pull the studs if possible. Do not be afraid of it, you will have it off before the other fellow gets back from the shop with the tack hammer.

[Marktjski1]

Ok folks.. Got it off.. Now.. Is there a drop in replacement for this motor? The pistons are rusted in place and the motor needs to come out.