EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

[HUNTING82]

Every fishing trip i go on, my motor starts fine, but when i'm running across the lake i lose a cylinder because the spark plug goes out what is the problem?<br /><br />1976 johnson seahorse 15hp

 

[Dhadley]

Re: EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

What plugs are you using?

 

[fireman57]

Re: EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

Are you sure you just aren't losing spark to that cylinder?

 

[HUNTING82]

Re: EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

I'm using ngk b7hs

 

[HUNTING82]

Re: EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

all i know is i'm losing a cylinder, so i replace the plug and then i will lose the other cylinder not long after

 

[fireman57]

Re: EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

Use the correct champions as these engines were designed around their heat ranges.

 

[fireman57]

Re: EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

When you drop this cylinder will it still idle okay? If it will idle then pull one plug wire at a time and listen for the change in rpm. Might be time for a new coil. Any cracked or have dark spots on them like they may have had too much heat?

 

[HUNTING82]

Re: EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

I only have two cylinders, the coils have never been replaced, almost 30 years old

 

[Dhadley]

Re: EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

Start with Firemans suggestion of getting the correct plugs. Then we can start from the begining.

 

[HUNTING82]

Re: EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

I talked to several boat repair shops and they told me the ngk and the champion were recommended for this motor, so i bought the ngk because they were out of champion

 

[CATransplant]

Re: EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

I think you'll find that the correct Champion plugs will outlast the NGK's by a good factor.<br /><br />How are you using this motor? If you're mostly trolling with it, you may need one grade hotter plug than if you're running it wide open most of the time.<br /><br />But do stick with the Champions.

 

[HUNTING82]

Re: EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

I run it wide open 95% of the time

 

[CATransplant]

Re: EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

If your engine has an "R" suffix in the model number, you need the Champion L82C plug. <br /><br />If your engine has an "A" suffix in the model number, you need the Champion UL81J plug.<br /><br />Get the right plug from Champion...put a pair of them in your motor. I'll bet your problems go away.<br /><br />Or, you can keep fouling those NGKs. It's up to you.

 

[DHPMARINE]

Re: EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

If I didn't have the correct Champion plug,I still wouldn't sell you an NGK for an OMC/BRP motor,unless it was a 4stroker.<br /><br />DHP

 

[Swider]

Re: EVERY TIME I GO OUT I'M HAVING TO REPLACE SPARK PLUGS WHY?

As I turned the fuel/air mix screw I reached a point where the motor ran smooth but fouled plugs as you described. I had to carry spares with me. I turned it out more. The motor began to run rough but I kept turning and all of a sudden it began to run smooth again. I left it there. That was 1 1/2 years and many fishing trips ago and I haven't replaced another plug.