Demoh
Member
- 217
- 26
- 18
- Location
- St Pete, FL
Had a friend purchase a gen up in PA and decided because a trip from FL for 1 gen would be pricey why not buy 2? Well I decided to pick up a cheap non-runner.
Ended up getting a unit that came back from Kuwait (seems like a pattern, I got a MMG25 from Kuwait a few years back) with 6000 hours on it. Pictures didnt show that the exhaust cover was missing. I knew it would be a lot of work for this unit and I figured the engine would be full of water. It is missing a few parts but as a unit to screw around with and as a secondary unit for my house should my 5 not cut it, Im not too worried.
Pulled the drain, even though dry, it had evidence of milkshake / water. Attempted to bar over the engine, the engine was excessivly hard to turn with a very high breakaway point. Basically the unit was seized where the starter wouldnt have been able to do anything to it but a breaker bar would. Ended up loosening the nut on the harmonic balancer as a result. Hit a dead stop. Tried other direction, dead stop again.
Pulled the lid, then exhaust and intake, definitely water in the rear 2 cylinders. An attempts to push the valves down to let the water evacuate failed. Pulled the injectors, barred the unit over and still hit the same dead stops. The unit wouldnt get to TDC for #4 rotating in 1 direction and #3 in the other. Looks like the rust/carbon/whatever has become enough to stop the rotation of this engine.
Filled the cylinders with seafoam and let them soak for an hour. Tried barring them over again and I was now able to rotate freely. Hooked batteries up and proceeded to spray a white car with black liquid. (I wish, I covered the unit with a towel which it blew off and still made a mess, but I had my friend move his car). Went ahead and filled the crankcase with oil after trying to flush a bunch out unsuccessfully. Cheapest oil I had was a 5w30 syn blend (my friend doesnt carry plain conventional at his shop because bulk oil is so cheap) so I went ahead and filled the crankcase, threw some seafoam in there as well.
Since the electronics on this unit are non-responsive I put a mechanical gauge on and began to deadcrank to get the cylinders properly evacuated and check oil pressure. 35 psi while cranking. Not bad.
Tomorrow Im going to see if I can get it to fire up... Im hoping I dont have to pull the head or rebuild the engine. I know its not ideal to run with all that rust on the walls and valves and head, but unless I get some compelling evidence / guidance to do so I really dont want to go that far.
So, if I pull the head could I reuse the headgasket or do those get destroyed when pulled apart? What is the consensus on this type of repair for what the next course of action is based on what has already been done? What do people use for gasket material for these units if one of the exhaust ports' gaskets is blown out? I took my IR camera to a running at 100% 802A and saw temps close to 600 so I can only assume the actual exhaust gas temp is like 800, and ultra copper RTV is rated at 700. Also, is the gasket on the side of the engine reusable? Basically im trying to open everything up that has reusable gaskets but not anything where im going to need to order a gasket.
So if I do get this thing to fire up without pulling the head, what re-break-in process should be followed? Should this be a fast and hot or a gradual bringing up the load? I figure I would get some things sloshed around and evaluate the oil, if it looks off in any way, change it. then bring it up to operating temp then check again, change it, then maybe check again at 1 hr. During this process should there be an additive in the oil because the rings may potentially be frozen? Pint of seafoam in each or some other magic in a can?
Ended up getting a unit that came back from Kuwait (seems like a pattern, I got a MMG25 from Kuwait a few years back) with 6000 hours on it. Pictures didnt show that the exhaust cover was missing. I knew it would be a lot of work for this unit and I figured the engine would be full of water. It is missing a few parts but as a unit to screw around with and as a secondary unit for my house should my 5 not cut it, Im not too worried.
Pulled the drain, even though dry, it had evidence of milkshake / water. Attempted to bar over the engine, the engine was excessivly hard to turn with a very high breakaway point. Basically the unit was seized where the starter wouldnt have been able to do anything to it but a breaker bar would. Ended up loosening the nut on the harmonic balancer as a result. Hit a dead stop. Tried other direction, dead stop again.
Pulled the lid, then exhaust and intake, definitely water in the rear 2 cylinders. An attempts to push the valves down to let the water evacuate failed. Pulled the injectors, barred the unit over and still hit the same dead stops. The unit wouldnt get to TDC for #4 rotating in 1 direction and #3 in the other. Looks like the rust/carbon/whatever has become enough to stop the rotation of this engine.
Filled the cylinders with seafoam and let them soak for an hour. Tried barring them over again and I was now able to rotate freely. Hooked batteries up and proceeded to spray a white car with black liquid. (I wish, I covered the unit with a towel which it blew off and still made a mess, but I had my friend move his car). Went ahead and filled the crankcase with oil after trying to flush a bunch out unsuccessfully. Cheapest oil I had was a 5w30 syn blend (my friend doesnt carry plain conventional at his shop because bulk oil is so cheap) so I went ahead and filled the crankcase, threw some seafoam in there as well.
Since the electronics on this unit are non-responsive I put a mechanical gauge on and began to deadcrank to get the cylinders properly evacuated and check oil pressure. 35 psi while cranking. Not bad.
Tomorrow Im going to see if I can get it to fire up... Im hoping I dont have to pull the head or rebuild the engine. I know its not ideal to run with all that rust on the walls and valves and head, but unless I get some compelling evidence / guidance to do so I really dont want to go that far.
So, if I pull the head could I reuse the headgasket or do those get destroyed when pulled apart? What is the consensus on this type of repair for what the next course of action is based on what has already been done? What do people use for gasket material for these units if one of the exhaust ports' gaskets is blown out? I took my IR camera to a running at 100% 802A and saw temps close to 600 so I can only assume the actual exhaust gas temp is like 800, and ultra copper RTV is rated at 700. Also, is the gasket on the side of the engine reusable? Basically im trying to open everything up that has reusable gaskets but not anything where im going to need to order a gasket.
So if I do get this thing to fire up without pulling the head, what re-break-in process should be followed? Should this be a fast and hot or a gradual bringing up the load? I figure I would get some things sloshed around and evaluate the oil, if it looks off in any way, change it. then bring it up to operating temp then check again, change it, then maybe check again at 1 hr. During this process should there be an additive in the oil because the rings may potentially be frozen? Pint of seafoam in each or some other magic in a can?