Piston rings

[Barbersham]

I'm quite confused about the rings on my 4 stroke. I am burning a quart every 5 hours and it was just rebuilt by a pro. He has built 500 engines and this is the first problem motor he has had. There are 0 leaks on the motor. First 5 hours I had it Died at full speed for no reason. I checked the oil and it was completely empty. I put a quart in and it was still a little below full. Didn't seize but wouldn't run. He pulled the timing cover and the belt shredded. Put a new belt on and the oil keeps disappearing. About 5-6 hrs a quart. Thought maybe rings didn't seat but I would imagine after 24 hrs drive time they would so took it back. He said the carb float was stuck and prolly flooded the cylinder so he cleaned it and put it back on. He said the exhaust was completely loose so he tightened it and he said that should fix it.

Well it didn't. I took it home and drove it a couple hours and it's at bottom of fill section. So I took it back. He pulled the head off and tore it apart but it was like brand new. He replaced valve seals anyways just in case. Exhaust loose again. When the head was off he showed me the cylinder walls and how clean they were. He showed me the nice line of oil the oil ring leaves in the cylinder above the piston. So hr put it back together.

I'm at a loss. I'm broke and I have a lemon.

[racin161]

Sorry for your problems we'll see if we can help. First off your pro should know there shouldn't be oil on top of the piston. I think there may be 2 problems. First when the cylinder was honed it was not honed correct for the rings (No Cross Hatch) to allow the rings to seat. Second would be the rings even though you have compression you have no oil control which again points to the rings not sealing. The ring end gap must be correct for the piston and bore if to wide again no oil control. At this point the piston and rings are going to have to be removed and really your starting all over. Probably why he is dragging his feet. You may want to have him do a leak down test first and that will tell where your leakage is Intake Valve/Exhaust Valve/ or crank case (Rings)

Good Luck
LOU

[Barbersham]

Thanks Lou. If the compression was 150 on one cylinder and 152 on the other can that still mean there is a problem? By oil on the piston I meant oil on the cylinder walls when piston goes down not physically on top of the piston.