spark plug orafice size

[medic2051]

Anyone know the size of the spark plug orafice on a 1975 johnson 50hp? I may purchase a used compression guage to check the motor, but am not sure of the size I need. <br /><br />Thanks

 

[Joe Reeves]

Re: spark plug orafice size

If you're speaking of the threads that the spark plug threads into, that would be 14MM, with the hole itself being approximately 5/8" to 11/16".

 

[medic2051]

Re: spark plug orafice size

Thanks, Joe!

 

[sikpnter]

Re: spark plug orafice size

How about for a 96 150 fast strike? I'm going to get a comp. tester also but had the same question that medic had thanks.

 

[Paul Moir]

Re: spark plug orafice size

Well, I see the '96 150 takes a QL78YC spark plug, which has a 14mm thread just like Medic2051's.

 

[sikpnter]

Re: spark plug orafice size

This site is priceless thanks!