Which plugs for 1960 10 hp QD

[Herm71]

My 1960 10 hp QD has Autolight 303 plugs now. I am not sure if they are the right plugs or not. They are pretty well shot. Which plugs work good?
Thanks

 

[Daviet]

Re: Which plugs for 1960 10 hp QD

Parts book calls for champion J4J.

 

[samo_ott]

Re: Which plugs for 1960 10 hp QD

Champion J4C is what my book sez. Or try J6C.

 

[1946Zephyr]

Re: Which plugs for 1960 10 hp QD

I wouldn't use a J4C for anything but a fishing weight. I would recemend the J6C myself.