83EL77S
J4758585
I was messing around with my old engine this afternoon and decided to put in the new plugs that have been sitting around. When I pulled out the lower Port plug, it looks pretty clean. All the rest of the plugs had a distinctive old 2-stroke look. I put the plugs back & torqued them down, then started the motor. The motor was running so I pulled off one of the plug wires and the motor slow down significantly, pretty normal... then I pulled off the lower port side plug wire and had no change.
One thing led to another and I did a compression test on the motor. Sure enough both port side cylinders were at 60 PSI and both starboard side cylinders were at 90 PSI...
The only work I did to this motor recently was removing the carburetors and changing the fuel lines. I've run about 36 gallons of fuel through this motor over the last few weekends. Never had any running issues at all.
Maybe a head gasket? Open to suggestions.