502-Mag-Mpi Plugs
Platinum Member
03-15-2003, 10:21 AM
#2
Guest
Posts: n/a
A little bit controversial, but...
I have installed RV15YC4 Champion spark plugs gapped at .045 in many different big block powered boats and they work very well. The extreme projection on the nose gives the spark plug a wide heat range and the plug is designed for a larger plug gap. Thats good, because with the long spark duration of the breakerless induction ignition, a wider gap really lights off the air/fuel mixture well between idle and 5,000 rpm. They are very easy to find at automotive parts stores because they are such a common plug (probably Champions biggest seller).
Sincerely
Dennis Moore
Sincerely
Dennis Moore
03-15-2003, 04:20 PM
#4
Registered
I had the exact same engine in my last boat. Had some problem with rough idling. Switched to Rapid Fire (#1 I believe) and MAN did they smooth the engine right out! Great acceleration and high end too.
03-16-2003, 11:04 AM
#5
Charter Member #1171
Charter Member
Same here ,,, rapid fire #1 ,,, cleaned up my transom to.
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I want to live in a world where a chicken can cross the road and not have its motives questioned.
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03-18-2003, 03:38 PM
#6
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Another vote for Rapid Fire #1. Did clean up the rear end on my 27' fountain. In addition to the plugs I have also set the timing to
12 deg advance (32 total advance), installed a K&N air filter , and added an EMI exhaust. These changes have really woke up the stock 502 carb motor.
12 deg advance (32 total advance), installed a K&N air filter , and added an EMI exhaust. These changes have really woke up the stock 502 carb motor.
