I'm needing some advice from someone who has some hands on experience in fixing this problem. I just purchased a 1974 MF 175 with the Perkins G4.236
gas motor w/2000 hrs. The price was right and there are a number of issues that I'm addressing. Needs brakes, PS wasn't working to good (adjustments on the cylinder fixed that), throttle shaft dropped due to worn out friction
washers (at first I thought it was the governor) waiting on parts. More pressing is the high oil consumption. Today I tore down the engine, cylinder head, oil pan, pistons. Prior to the teardown the compression was at 150 psi across the board on compression check. Oil pressure is very good and the rod bearings all look like new. Engine idles at 725 rpm give or take 15 rpm. I have, and know how to use, the factory manual and operators manual, no parts manual at this time. Head is going to machine shop tomorrow to check guides and stem seals. The BIG problem I'm having is what to do about the rings/liners. The pistons all look good as well as the liners. No scoring, no gouges, nothing. Cylinder ridge at maybe 0.001-0.0015, it barely catches your fingernail. All rings were free and turning none broken. I will be checking bore taper tomorrow if I can find the specs, which I can't. The manual says max 0.006 taper for the Continental but for the Perkins it says renew when
performance dropoff dictates. How lame. So my question is how many if any of you have honed out the cylinders and re-ringed the pistons with good luck?
I really don't want to go for liners if I don't have to. Thanks in advance.
PS
gas motor w/2000 hrs. The price was right and there are a number of issues that I'm addressing. Needs brakes, PS wasn't working to good (adjustments on the cylinder fixed that), throttle shaft dropped due to worn out friction
washers (at first I thought it was the governor) waiting on parts. More pressing is the high oil consumption. Today I tore down the engine, cylinder head, oil pan, pistons. Prior to the teardown the compression was at 150 psi across the board on compression check. Oil pressure is very good and the rod bearings all look like new. Engine idles at 725 rpm give or take 15 rpm. I have, and know how to use, the factory manual and operators manual, no parts manual at this time. Head is going to machine shop tomorrow to check guides and stem seals. The BIG problem I'm having is what to do about the rings/liners. The pistons all look good as well as the liners. No scoring, no gouges, nothing. Cylinder ridge at maybe 0.001-0.0015, it barely catches your fingernail. All rings were free and turning none broken. I will be checking bore taper tomorrow if I can find the specs, which I can't. The manual says max 0.006 taper for the Continental but for the Perkins it says renew when
performance dropoff dictates. How lame. So my question is how many if any of you have honed out the cylinders and re-ringed the pistons with good luck?
I really don't want to go for liners if I don't have to. Thanks in advance.
PS
