melted down spark plug

[cruzzer]

i have a 1983 170 hp 470 mercrusier in a 24ft. Citation. did a recent tune up, plugs, wires. and changed from points to electronic ignition. well first thing i noticed was a loss of rpm (only getting to 3500), then bang , the #4 plug came apart, the insulator came right out of the threaded base. it was glowing red hot!! my guess is the timming must be way off, but it wasn't moved as far as i know. what should be my first move. thanks<br /> cruzzer

 

[Rex]

Re: melted down spark plug

FIRST CHECK YOUR WATER OR TH THE IMPELLOR<br />I HOPE YOU DID NOT HURT THE ENGINE<br /> REX

 

[ODDD1]

Re: melted down spark plug

Cruzzer, is real simple....boat ran before?....you worked on boat? now boat not run as good?...<br /> ALWAYS, ALWAYS, ALWAYS go back to what you screwed with last...as soon as you introduce another set of 'variables'[like carb,cooling etc] troubleshooting becomes much harder...<br />part of a "tune up" IS setting timing and verifying the advance works.....