Recommended Spark Plug failed.

[ronaca88]

FunTimes, the sparkplug in my hand is the 41-993, here is a picture from my manual that came with the boat. It mention to use either 41-993 or 41-101.


Thats exactly what blown my mind, if they are in good shape, then whey la engine started right after I changed the 8 sparkplugs.

I mean, thats cant be a coincidence, something where wrong with these spark plugs.

So, if I would like to try a conventional ones, you recommend the R44LTS but those are black im afraid about corrosion, is there another with chrome or nickel?

 

[Fun Times]

So, if I would like to try a conventional ones, you recommend the R44LTS but those are black im afraid about corrosion, is there another with chrome or nickel?

AC doesn't seem to make a Marine grade plug for the 44LTS number. The M at the front make it a marine plug. As often as you seem to be going through sparks plugs right now, rust buildup on the outside of the plug isn't going to much of an issue.:bolt: Are you running in a saltwater environment? Many members do use a non marine rated plug successfully.

The 44LTS plug was more to try and help you get to a closer heat range of NGK's 4 rating while using a conventional...But it's still not an exact match as when you cross the ITR4A15 # over to most conventional NGK's, On average it comes up as a 5 heat range. Denso has the biggest list of cross over numbers to view, http://www.sparkplug-crossreference.com/convert/NGK_PN/ITR4A15

http://parts-catalog.acdelco.com/catalog/interchange.php

Maybe try Ohms checking all your old plugs.

 

[boatman37]

i just replaced my plugs. the PO said he hadn't replaced them in about 5 years. they were MR43T's and still looked pretty good. i put the same thing back in it