Gaps

[noah4009]

Hi
I have a 1971 Chrysler outboard motor. Model number is 557HC Serial 3188What plugs should I use and what is the proper gap for the plugs and points Any and all specs will be greatly appreciated.
Noah

 

[Frank Acampora]

Re: Gaps

If it is a standard ignition engine, then use Champion L4J. Since I think these plugs are no longer made, substitute NGK B8S. Gap to .030 or .035.

If it is electronic "Magna Power" ignition use Champion #322 (UL18V or L20V.) Substitute NGK BUHX or BUH. These are surface gap plugs and gap is set permanently when manufactured.

Do not substitute these plugs in a standard ignition engine. It does not have enough voltage to adequately fire them. The engine will run at high throttle settings but will not idle and will be almost impossible to start.

 

[noah4009]

Re: Gaps

Hi Frank
I was told this boat is not magna power on another post when I was trying to find out this. This motor is 2 cylinder and was told it is not. I got this boat from a friend who tried to tune it and striped the plug port. Boat never ran again. The plug he used in it was a champion L77JC4. But he knew as much about this as I do. NOTHING.
Thank You
Noah