Autolite replacement for RJ12C

[flycavalry]

I am trying to determine if the correct plugs are installed in my A4. Currently I have Autolite 306 resistor plugs installed. Is this the same plug that is listed as the replacement plug for the RJ12C in the Moyer parts catalogue?

[Mo]

cross reference link

Welcome aboard.

Here's a cross reference link.

http://www.sparkplug-crossreference.com/

[David Masury]

I use the Autolite 437 plug... it is a bit hotter but I have never had any troubles with carbon etc... use the same plug in my 1941 Ford tractor.

David

[Dave Neptune]

Fwiw

I remember a very interesting "spark plug" post by Daniel (Ball Racing) regarding heat ranges and plug reaches. I don't remember the plug's numbers though. I would like to give them a try.

Dave Neptune

[sastanley]

ask & ye shall receive

Dave,
A quick search reveals --> http://www.moyermarine.com/forums/showthread.php?t=6424

[CalebD]

Autolite 437's

... have worked well for me.

[sastanley]

Caleb,

I've used those with good success too.

I've had all of the following in the engine at one point or another:

Champion
RJ8C
RJ12YC

Autolite
303
437

currently running & happy with:

NGK BR6S in #1 thru #3
RJ12YC in #4 (weaker cylinder so I am running a slightly hotter plug to help keep it from fouling..Dave Neptune's idea! )