Spark plug gap = Low RPM?

Richman

Seaman Apprentice
Joined
Jan 31, 2007
Messages
36
My 1998 Ocean Runner will not rev to over 4200 at WOT while pushing a rather light Sea Era (Sea Fox) 230 W/A. I have not really dove into the problem yet. It runs very well and pushes me to 37 mph, so maybe the tach is wrong adn I am getting full RPM's. I have pulled the boat out of the water and decided to change the plugs the other night. I found that the old plug's gaps were,huge! I could have slid a thin dime in there. I put new plugs in but it will be a week or two to get it back in the water.

What would a symptom of over-gapped plugs be? Would lower than reasonable RPM be one of them??? And if not, what would you all think would be another cause. The boat planes at about 3300. It's not that it runs bad, I just want to get a bit more out of it adn think that those few last RPM's are there somewhere.
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Spark plug gap = Low RPM?

What plugs were in it?

What brand & pitch prop are you running?
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: Spark plug gap = Low RPM?

Has it been like this since you got it, or has performance been deteriorating over time?

Are you trimming the motor out as it comes up on plane?
 

rudedude

Petty Officer 1st Class
Joined
Aug 20, 2007
Messages
293
Re: Spark plug gap = Low RPM?

Too wide a gap will make the motor run poorley, and miss.
 
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