Curious what brand spark plugs people are running in their boats these days. My 6.2's are due for a change.

Dave

AC Delco or NGK.

Here is a nice cross chart. I use delco now, was using NGK

http://www.dragstuff.com/techarticle...reference.html

If you choose to use NGK make sure you buy them from a reputable source. If you search for the best price on-line and they are from a not well known source, you can very well end up with black market copies that look exactly like the originals, even the box is a near dead on copy. The market has been flooded with these Chinese knock-offs.

I know with a car I replace based on miles

what are some of the performance issues with a boat that would indicate that the plugs needs to get changed out

I know this is a dumb question - but I'm really new to this mechanical stuff --

3pointstar

It really depends I guess. IMO a high performance boat should get new cap, rotor, and plugs every two years.....wires every 4. Boats run a higher average EGT than a car, are stored for long periods, and are in a harsh environment all the time.

do you use the stock 575 csi plug heat range?. Found out the yr5s i have been running are a lot hotter

I must be over the top.. I do it every year lol.. That was with my 600SC though. I will probably do every 2 with the 502's in the new boat

Wires: 10+yrs on stock black motors.
Regular plugs - every 2-4yrs. Same with cap/rotor. Black motors again.
Platinum/Iridium - when you feel like it. 5+ yrs probably a good time to replace.

Above on fresh water and usually covered boats.

High performance engines - before they get used up. LOL.

I was using mr41t which is stock. This year I tried 42ts because I was fouling down low, but it turned out to be a fault map sensor on one that was intermitten. I am going back to the mr41t this week