Spark plug gap

Wally91

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Jul 24, 2020
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So I’ve been doing some research and it’s just a big cluster ****. But I’ll tell you what I found out I started stock .02 or .025 but I went bigger .03 ran good I thought that was it then I said screw it opened it to .04 and she runs better than ever now I’m afraid to go bigger though any input is appreciated.
 


Vikingimike01

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Jul 1, 2018
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1,396
Maybe you got a very good magneto? Lol. I don't know. Maybe people say that spark gap is good because of the low quality magnetos.
 

Wrench

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Nov 14, 2018
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So I’ve been doing some research and it’s just a big cluster ****. But I’ll tell you what I found out I started stock .02 or .025 but I went bigger .03 ran good I thought that was it then I said screw it opened it to .04 and she runs better than ever now I’m afraid to go bigger though any input is appreciated.
Small gap, quick short weak spark.
Large gap, long big weak spark. Makes a normal coil work hard but OK if ya got a strong coil. S/P electrode wears out fast
Recommended gap. strong spark and best for your engine.
Too big of a gap, spark can jump sideways or misfire.

Also there is more hydrocarbon/02 mixture floating by to be ionized.
The longer the spark duration the more chance to find some hydrocarbon/02 to ionize.
 
Last edited:

Chainlube

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Jan 5, 2020
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1,640
Alls we got is a mag and a CDI, if the capacitor is sufficiently charged the spark will travel across the gap. Too big of a gap and spark won't travel. If you use a NGK B6HS plug, it has a little longer reach than the stock plug so it puts the spark deeper into the head.
 

Wally91

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Jul 24, 2020
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3
Are you running any extra compression or stock?
I cut the baffle off and put a better air intake on it’s hard to get it started no matter what gap but once I get it started it runs and restarts no problem I probably created an issue messing with the exhaust but it runs great
 
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