spark plugs...

hotmerc

Seaman
Joined
Aug 13, 2003
Messages
71
at the begining of the season i had changed my spark plugs. my engine is a 1987 mercruiser 5.0 model 230 that had champion RV15YC4 traditional plugs. i was to believe that they were original plugs that came with the boat. i put the autolite equivelant, which are autolite #25, to the champion plug in. motor seems to run well with them. but after talking with a mechanic in the yard, he says that i put in the wrong plug, it's not as "hot" a plug as the champion, which is the spec plug for this patricular motor. i think he's crazy. i would think a platinum plug or a split fire would be a hotter plug than the traditioal champion. i also hear that NGK plugs are now original equiptment in mercruiser. can anyone shed some light on this for me?<br /><br />thanks
 

cobra 3.0

Lieutenant Commander
Joined
Jul 31, 2003
Messages
1,797
Re: spark plugs...

I put some platinum NGK's on my motor 3.0 OMC, but in the same heat range as specified. I saw no difference. Even if it's platinum, it still should be in the same heat range. Platinums work better and longer at keeping the original spark. They are not hotter because they are platinum.
 

hotmerc

Seaman
Joined
Aug 13, 2003
Messages
71
Re: spark plugs...

hey, thanks for the input. i always thought that the platinum plug was better for cars, why not for boats. i'm considering using an autolite platinum racing plug, made for higher rpm engines, its got to be better than traditional copper core plugs.
 

crazyray

Petty Officer 2nd Class
Joined
Jun 19, 2001
Messages
134
Re: spark plugs...

a spark plug does one thing light that fuel mixture, simple it only see a difference if you are questionable in your tune up anyways, an spit fire or u grove plug may help just a little if you are say a bit rich but you not going to feel that, the only thing you feel is that tingle in the wallet after buying those high dollar wonders and no positive results. keep it simple there very little gain here except for the the parts co.
 

chris in va

Chief Petty Officer
Joined
May 4, 2003
Messages
410
Re: spark plugs...

Um, well...about the platinums being hotter. Not sure about the other copycats out there, but the Bosch Platinum is a 'cooler' plug due to the ceramic totally encasing the electrode, amongst other things.
 

hondon

Lieutenant Commander
Joined
Jun 11, 2001
Messages
1,922
Re: spark plugs...

Mercruiser is using AC plugs on most of their products,however they are using alot of platinums now because of the hotter ignition output currently out there.A plug that crosses to your OEM reccomended plug will do fine unless you have some special needs.
 

hotmerc

Seaman
Joined
Aug 13, 2003
Messages
71
Re: spark plugs...

after doing a little reaserch, i have cross referenced my original mercruiser RV13YC4 plug to the autolite high performance racing plug (AR24). its not a platinum plug, but it has the same heat range and its designed for high rpm motors. thanks alot for all you input guys.
 
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