Posted by Bill Wincapaw on March 19, 1998 at 17:17:57:
In Reply to: Spark Plugs Explanation posted by T.KRALOVIC on March 19, 1998 at 11:09:32:
T
Your running a J-14 J is the plug type 14 is the heat range barring carb & elec problems if the electrodes are black(sooty) then the plugs are to cold then you need a hotter plug ( J-15 or16 ) if the electrodes are white then the plug is to hot you need to go to a colder plug ( J-13 or J-11) if the plug is tan then leave it alone ( J-14) . The 24 v (shielded) plugs on the M-37 is 2243 or 2245 (hotter) the auto parts should be able to cross these numbers over to a civilian plug number & matching heat range. Hope this is what you were looking for.
Regards,
Bill Wincapaw