Spark Plugs

[Mike722]

I have a 1994 Mariner 40hp 4cylinder 0G48873 on a pontoon boat. I purchased it last year. The plugs in the engine are NGK BUHW, however the manual calls for BUHW-2.

Does anyone know of a service bulletin or good reason why BUHW are in this engine? I have put about 53 hours on the engine this year and it appears to run fine.

Thanks for your help
Mike

 

[Laddies]

Re: Spark Plugs

In my latest NGK book. in the specification section it say the BUHW is one heat range hotter the the BUHW-2. Last year when I called their service hotline to check on heat ranges of the two plugs for our racing engines I was told by the tech rep. they were the same heat range but the BUHW-2 had a .005 larger gap to generate more firing voltage on the ADI systems. So who knows, he!! I don't, plugs can generate almost as many arguments as OIL I don't know of any service bulletins
Some of the most common reasons plug get superseded are people using the cross referance charts, from other manufactures or distibuters, manufaturers in most cases say to not use the charts to go to the model listings. Lazy or inept parts and service personal not taking the time to look up the right plug. Someone not having the right plug availibile and the plugs are bad so putting in what they have so the can get on the water, then forgetting about changing to right plug later because the engine seemed to run alright ( I think we have all done this one on the boat, weedwhacker or something, it's not a perfect world and neither are we) I think I"m probably the only dumb enough to try to anwser this question--Bob

 

[Mike722]

Re: Spark Plugs

Thanks for the info, it is consistant with what I have found and was thinking. I was planning to go back to the BUHW-2 per the manual, unless someone had a reason why I should not.