Spark Plug Gap for Yamaha 9.9 4 cycle

yamaha chris

Cadet
Joined
May 20, 2008
Messages
10
Does anyone Know or Know where I could find the spark plug gap spec. for a 99 Yamaha 9.9 High Thrust 4 stroke outboard.

Thanks
 

CatTwentyTwo

Chief Petty Officer
Joined
Jan 11, 2005
Messages
425
Re: Spark Plug Gap for Yamaha 9.9 4 cycle

For what it's worth, I have the Yamaha owner's manual and service manual for a 95 T9.9. The owner's manual says .020 to .024, the service manual says to gap the plugs at .024 to .028.
 

yamaha chris

Cadet
Joined
May 20, 2008
Messages
10
Re: Spark Plug Gap for Yamaha 9.9 4 cycle

Thanks Ryoung
I would think they would be the same.

Thanks
Chris
 

BruceAML

Petty Officer 1st Class
Joined
Feb 26, 2007
Messages
371
Re: Spark Plug Gap for Yamaha 9.9 4 cycle

You need to post the complete model number from the data plate. The gap can be found in the genuine Yamaha owner's manual or the genuine Yamaha service manual. If your motor uses an NGK CR6HS spark plug, the gap is .024. You need to torque the spark plug when it is installed.
 
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