Last year Motor started & ran fine at power for about 5 minutes then bogs down and will not restart. Cranks freely with spark and no overheat (touch test). After ~ 1/2 hour cooldown can start and run at low power by toggling choke. Found large quantity of water in fuel (no seperator but have one to install). Fresh gas & drained carbs but problem persists.
After complete cool down behavior repeats. During one episode noticed that plugs were unusually clean. Fogged last fall and found some rust on spark plugs this spring.
Head gasket replaced 4 years ago (removed head to helicoil stripped plug hole - shame on me). All other head, cooling & exhaust gaskets original. Motor has been used annually since 1971. Have original OMC shop manual.
Plan compression check cold and hot before any disassembly. Can I identify a leaky head coolant gasket from a leak between exhaust water side and cylinders (either gasket or parts) based on readings ? Is a teardown of suspect parts the definitive answer ?
My family has an emotional attachment to this boat (1966 MFG Corvette purchased by my dad) but summers are short in Maine and I am loosing interest in prolonged repairs. My 2003 Glastron Fish & Ski beckons like a siren on a rock.
Any help would be appreciated.
Bumpa53
After complete cool down behavior repeats. During one episode noticed that plugs were unusually clean. Fogged last fall and found some rust on spark plugs this spring.
Head gasket replaced 4 years ago (removed head to helicoil stripped plug hole - shame on me). All other head, cooling & exhaust gaskets original. Motor has been used annually since 1971. Have original OMC shop manual.
Plan compression check cold and hot before any disassembly. Can I identify a leaky head coolant gasket from a leak between exhaust water side and cylinders (either gasket or parts) based on readings ? Is a teardown of suspect parts the definitive answer ?
My family has an emotional attachment to this boat (1966 MFG Corvette purchased by my dad) but summers are short in Maine and I am loosing interest in prolonged repairs. My 2003 Glastron Fish & Ski beckons like a siren on a rock.
Any help would be appreciated.
Bumpa53
