Which spark plug should i use surface gap or gapped plugs on 88 yamaha 130hp

jgelsthorpe

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Jul 3, 2011
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I had carbs rebuilt and the mechanic said that i should change my spark plugs to a gapless plug(surface gap) . It has a b9hs-10 ngk and he gave me a buhw ngk and everything is the same except this one is a surface gap. He also said that it would give motor a faster wholeshot than a gapped plug . And i just don't know and want different opinion before i put these plugs in and burn hole in pistons.
So if you have knowledge in yamaha please give me your advise.
 

jgelsthorpe

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Re: Which spark plug should i use surface gap or gapped plugs on 88 yamaha 130hp

He also said that it would start easier (cold blooded)
 

Silvertip

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Sep 22, 2003
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Re: Which spark plug should i use surface gap or gapped plugs on 88 yamaha 130hp

He should also have recommended the plug that Yamaha recommends for the engine. Your owners manual should contain the proper plug. Surface gap plugs are not all they are cracked up to be either. Engines and ignition systems are designed around them so one also needs to be mindful of heat range when switching between plug designs.
 

jgelsthorpe

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Re: Which spark plug should i use surface gap or gapped plugs on 88 yamaha 130hp

Yeah I don't have the original owners manual. But there is a sticker inside the cowling on bottom that says to us0e that ngk b9hs-10 so that's what I put unit and when I bought boat a month ago when I was going through it had b7hs-10 . So I put what sticker said to use . But It didn't really seem to help or hurt anything . I am trying gain a little better wholeshot without changing prop pitch because don't want to lose any top speed . But if I can't gain any wholeshot . I will just have to deal with it . Or upgrade to a newer boat LOL. Maybe you have any suggestions on how to gain a little .
 

RandyJ

Master Chief Petty Officer
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Jun 13, 2002
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Re: Which spark plug should i use surface gap or gapped plugs on 88 yamaha 130hp

Do you have a need for a better hole shot? I only need that if I'm racing or trying to jerk water skiers up. I tend to just like to ride fast and am very sensitive to gas mileage.... so that's what I try to tune my engine(s) for. Otherwise, I like to troll fishing so that's important too.
 

Silvertip

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28,758
Re: Which spark plug should i use surface gap or gapped plugs on 88 yamaha 130hp

The more important number is does the engine rev at or very near the top of the manufacturers recommended wide open throttle rpm band with what you consider an average load. If it can't get there, you need a different prop. If it tends to over rev you need a different prop. If it is within the band or slightly above it then what you have is what you get. It doesn't get any better than that. Adjusting engine height (not trim) may help some. Where is the AV plate in relation to the bottom of the boat?
 

Ldavidgrover

Petty Officer 2nd Class
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Feb 22, 2012
Messages
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Re: Which spark plug should i use surface gap or gapped plugs on 88 yamaha 130hp

Stick with what the manual states. You cant go wrong
 
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