Post Number: 7
|Posted on Tuesday, August 09, 2005 - 08:40 am: ||
I have recently restored a P55 and have returned the enigne back into the boat but after running for a couple of hours the engine has become very tough to turn over. It seems to have seized slighly but is still possible to turn the engine over extremely slowly but I do not want ot cause any more damage if there is any. Can't think what could of caused this. I have plenty of oil in the gearbox and have the correct fuel/oil mixture (50:1). Any suggestions would be very helpful.
Post Number: 168
|Posted on Wednesday, August 10, 2005 - 08:12 am: ||
Did you keep the water passages wet when it was out of the boat. Some say that the rust around the cylinders can exert such pressure that the pistons can become seized. Whether it is true but many of us have seen cylinder split on the outside by the pressure build up from expanding rust inside cylinder water passages. I've also seen a Stuart with a splet straight across one of the cylinders.
Notwithstanding one should always clean out the coarse rust scale from all nooks and crannies inside the water passages when you do an overhaul.
Why don't you try it by taking off the water jacket (oval) cover plate and the expansion chamber cover plate and go to work, particularly around the cylinder walls. Be carful that you remove any large chunks as it's not easy to get some out at both ends (near the lenses/welch/core plugs)of the cylinder when it's on the engine.
Finally, fill water jacket with water and leave for a while and then try to turn it over again.
It may not be the complete answer but should have been part of the overhaul anyway.
Post Number: 1
|Posted on Monday, September 26, 2005 - 07:37 pm: ||
A friend of mine had a semilar seize up in his 2 cycle engine . It was in a small homebuilt aeroplane with a 35 hp engine with a 50 to 1 oil mix . After finally reading the engine makers warning and testing his petrol , he traced it back to 5 percent alcohol had been mixed with the petrol at the refinery . He had always asked when buying petrol , but the pump was not correctly labeled to warn of a alcohol mix . The refiners sometimes do this to lower smog emissions on a seasonal basis . Seems the alcohol doesn't allow the oil in the gas to stick and work well on the cylinder wall . He was luckey when his engine seized up and only had a minor forced landing and a ruined piston . Not shure why yours seized up , but it's something to think about .