NorthRising
Recruit
- Joined
- Feb 17, 2014
- Messages
- 2
Mercury 8 HP 2 Stroke (Serial number: 9464068):
The compression in the cylinders is 91 & 92 psi respectively (measured cold), so I think that is good as they are pretty much equal, but is 91/92 a high enough value?
- The engine starts easily and I've run it in a tank.
- I have a good tell-tale of coolant water.
- After a while though it cuts out, re-starts ok but will then again cut out.
- It will cut out whether idling or in gear.
- I think the engine is a little bit more smoky than it should be.
- There is a steady trickle of pale brown substance down the aft edge of the leg from below the lower cowl from what I think are known as exhaust reliefs (two holes); this seems to be an emulsion of unburnt oil and ?water? (this was also what we saw on the delivery trip and didn't like the look of), is this normal - could this be a symptom of a blown head gasket?
Background: this engine came with my boat and was de-winterised (2009) for the surveyor who got it to start, it was then re-winterised until I got the boat seaworthy. It was then de-winterised May (2010) and was supposed to be serviced, but the yard let me down and although they kept promising it would be ready at launch they left it too late, and when they tried to start it they found only one cylinder firing and replaced some electronic control unit; when I came to collect they let me know they had not serviced it, but it was running ok. I then managed to relocate the boat, but half way through the engine went a bit odd and as parts of the trip demanded a reliable engine I bought a new one.
Until today the engine has sat on a bench but I want to decide whether to get it up to scratch as a reliable spare or sell it, or break it and sell the parts....
The compression in the cylinders is 91 & 92 psi respectively (measured cold), so I think that is good as they are pretty much equal, but is 91/92 a high enough value?
- The engine starts easily and I've run it in a tank.
- I have a good tell-tale of coolant water.
- After a while though it cuts out, re-starts ok but will then again cut out.
- It will cut out whether idling or in gear.
- I think the engine is a little bit more smoky than it should be.
- There is a steady trickle of pale brown substance down the aft edge of the leg from below the lower cowl from what I think are known as exhaust reliefs (two holes); this seems to be an emulsion of unburnt oil and ?water? (this was also what we saw on the delivery trip and didn't like the look of), is this normal - could this be a symptom of a blown head gasket?
Background: this engine came with my boat and was de-winterised (2009) for the surveyor who got it to start, it was then re-winterised until I got the boat seaworthy. It was then de-winterised May (2010) and was supposed to be serviced, but the yard let me down and although they kept promising it would be ready at launch they left it too late, and when they tried to start it they found only one cylinder firing and replaced some electronic control unit; when I came to collect they let me know they had not serviced it, but it was running ok. I then managed to relocate the boat, but half way through the engine went a bit odd and as parts of the trip demanded a reliable engine I bought a new one.
Until today the engine has sat on a bench but I want to decide whether to get it up to scratch as a reliable spare or sell it, or break it and sell the parts....