Reply To: ’56 Lark rebuild: Unusual noise at piston/rod/crank preassembly

[Bob Wight]

It’s sure not normal.   In looking at your 2nd video there is some slight play in the rod or wrist pin but the knocking noise at TDC is much louder.   I think I’m with Tubs on this one – sounds like a rod cap or the crankshaft is contacting the case during rotation but not sure why that would be.  I’m afraid you’ll have to open it up again to look for rod or crank interference in the case.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1957 Evinrude 3022
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20
1982 Evinrude 25hp

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."