Thread:

R44T spark plugs and 099 heads

I've been running these plugs since it's what the boat came with when I bought. Just wondering if I should continue running them. Also, with HEI ignition, what sould the gap be?

Originally Posted by N2GLOCK

I've been running these plugs since it's what the boat came with when I bought. Just wondering if I should continue running them. Also, with HEI ignition, what sould the gap be?

IMO, you have the answer in your hand when you're holding a plug. Go back and reference some of the many "Plug reading" threads, look for illustrated charts as to color and heat tracing... A simple example: Is the plug wet? (or wet looking), Is the plug "white"? Is it sooted black? Most often these various conditions can be related to A/F ratios, but a plug(s) that is/are constantly in a "fouled" condition could be "too cold" in the heat range spectrum... How does the engine "cold start"??? Is there evidence of plug tip/strap erosion? Are there little shiny things imbedded on the "body" ends? (A sure sign of detonation)..... AND, what condition, causes, lead you to believe you might have the wrong heat range?..... As I recall, a standard automotive HEI application calls for .060 plug gap. And again, as I recall, a standard GM HEI is rated somewhere around 45K, ( A Vertex Mag is rated at 24K and calls for a .018-.020 gap). Those HEI factory distributors are pretty much bullet proof bone stock unless, and until, the module takes a crap.... Carry a spare module, change the "suppression" wires every couple of years, and the cap and rotor as required by visual inspection, and you should have many, many hours of happy, trouble free boating in your future with those R44T plugs....
Ray