Hi. I have a 1996 88 SPL that I rebuilt this past winter and now have about 4 hours break-in time on her. I have followed the break-in procedure to a tee including oil pre-mix (no VRO). She starts, idles and runs great?no problems there. Now here is the concern which was not noticed until the 2nd time I took it our following the 1st full hour of break-in. Between approx 2500 ? 3500 RPM I can hear a distinct clicking that seems consistent with the RPM, can?t hear it before of after that. I wouldn?t call it a knock as it sounds higher pitched. Kind of reminds me of the days we placed baseball cards in the bike spokes.
So following some advice I read here I tried to check for rod bearing play in each cylinder by inserting a drift through plug holes and checking for any piston movement / play about TDC and found nothing. I followed that up with a compression test and got 130, 120, 120, 120. When I rotate flywheel by hand with no plugs I cannot detect any noise / clicking, etc. other than water pump impeller friction in lower unit.
Now I did notice that, when turning the flywheel by hand, there seems to be some play in the crankshaft at the upper bearing area that I can feel & hear if I push & pull on the flywheel. I have no idea if I had this same play before the rebuild as I had never looked for, nor noticed it. I have a second parts motor which I checked against and did not feel any play in that motor, however that motor is somewhat bound up so I?m not sure it?s a good benchmark. Would anyone know if this ?play? is somewhat common and should be of concern? The bearings seemed to look and feel fine at rebuild so I didn?t replace.
Crankcase items I did replace: all wrist pins, clips & WP bearings, center main bearing. Rod cap bolts, 2 new pistons, all new rings (1 bore & 3 honed) all new seals. I did not replace upper nor lower bearing assemblies as they both seemed fine and did not replace large crank rod bearings as they seemed fine as well.
I rebuilt the motor because I broke a ring in one cylinder (#3) and was actually missing a section of piston between the rings on another (#1).
So following some advice I read here I tried to check for rod bearing play in each cylinder by inserting a drift through plug holes and checking for any piston movement / play about TDC and found nothing. I followed that up with a compression test and got 130, 120, 120, 120. When I rotate flywheel by hand with no plugs I cannot detect any noise / clicking, etc. other than water pump impeller friction in lower unit.
Now I did notice that, when turning the flywheel by hand, there seems to be some play in the crankshaft at the upper bearing area that I can feel & hear if I push & pull on the flywheel. I have no idea if I had this same play before the rebuild as I had never looked for, nor noticed it. I have a second parts motor which I checked against and did not feel any play in that motor, however that motor is somewhat bound up so I?m not sure it?s a good benchmark. Would anyone know if this ?play? is somewhat common and should be of concern? The bearings seemed to look and feel fine at rebuild so I didn?t replace.
Crankcase items I did replace: all wrist pins, clips & WP bearings, center main bearing. Rod cap bolts, 2 new pistons, all new rings (1 bore & 3 honed) all new seals. I did not replace upper nor lower bearing assemblies as they both seemed fine and did not replace large crank rod bearings as they seemed fine as well.
I rebuilt the motor because I broke a ring in one cylinder (#3) and was actually missing a section of piston between the rings on another (#1).
