Hi, I'm trying to un seize a yanmar 3gm 30. I have a loaded the engine with marvel Mystery oil, squirted PB blaster into the injector holes and after three weeks I was able to move the fly wheel counter clockwise 30° but it won't move clockwise any more than 5° either way with the breaker bar and socket .i'm starting to round the corners on the nut that holds the pully on to the crankshaft so I need to buy another nut but I'm not sure of the thread size and thoughts on the seized engine next step?anyone out there help me with that? thank you very much for all your help christian
Yanmar 3gm 30 engine seized
- Thread starter hunter healer
- Start date
How long has it been since the engine was run?
The first thing that I would consider is that it could be loaded with water or fuel. Did you release the pressure valves on the top of the engine?
Mike
The first thing that I would consider is that it could be loaded with water or fuel. Did you release the pressure valves on the top of the engine?
Mike
Are you using a six-point socket, or a twelve-point. The former is preferred.
I've been trying to avoid pulling the head! Under the valve cover the rocker assuming looks perfect no signs of water! One of the decompression levers was frozen I'll fix that and see if it makes a difference! If I go the route of pulling the head I'm afraid of snapping an exhaust manifold bolt or the intake bolts? Any special instructions on removal sequence of the head removal available
The question is, why did it seize. It could have a bent rod, broken valve (or spring), a broken piston, that would allow it to turn a few degrees and no further.
The motor turned over easily four years ago when I bought it but at that time there was some water in the intake manifold no water underneath The valve cover with the injectors removed and the decompression levers and place it turned over
I remove the valve cover and then remove the rocker assembly and pushrods but I'm thinking could it be that the decompression levers have to be pushed down in order for the Engine to turn over
If you removed the valve train ,it's going to be very difficult to turn the engine over ,as the valves now won't open it all to decompress.
If the injectors are out, there can be no compression lock. As I noted in a previous post, the head needs to come off . Then you can bump the pistons with a hammer and a wood block. bumping should be on port/starboard sides of the individual pistons to gently rock them in the bores and loosen the rusted rings.. A broken stud is not a problem in an engine that is frozen already.
Ok I guess it's time to remove the head! Question can it be removed with the intake and exhaust manifolds attached?
Question I'm installing a data marine transducer that has 2 o rings to seal out water leaking. I replaced the mushroom receiver and I want to know if I should lube the o rings or the receivers slightly with something when I push them inside the receivers? I don't want them to roll off the transducer as I put them in place
Question I'm installing a data marine transducer that has 2 o rings to seal out water leaking. I replaced the mushroom receiver and I want to know if I should lube the o rings or the receivers slightly with something when I push them inside the receivers? I don't want them to roll off the transducer as I put them in place
