Yamaha T9.9

[Fishinak12]

Hello all-
How are ya? Good I hope! Happy spring!
I am pulling my hair out trying to fix my kicker. It’s a 2014 Yamaha T9.9 high thrust.
Near the end of last summer if suddenly wouldn’t start (ran fine the day before). After awhile it DID start but ran crappy. Over the next two day it became progressively harder to start and ran crappier. I removed from boat for winter and brought into the garage.
i replaced the spark plugs, replaced fuel line connection, replaced fuel pump, and rebuilt the carb (which was nearly spotless). Now it’s back on the boat but won’t start at all. Even w spraying starting fluid in air intake.
I pulled the plugs, they are dark and wet (so getting gas rite) and I grounded plugs and confirmed there was a spark.
so I had spark, and I have gas! What am I missing!? Why wound this sucka start?
please any and all suggestions greatly appreciated!
Thank you!

 

[racerone]

Little steps here.----So spark jumps the gap on a sparkplug.-----But you need to test the maximum output of the system.----So does spark jump a gap of 5/16" ( 8 mm ) or more , yes or no ?

 

[Fishinak12]

Little steps here.----So spark jumps the gap on a sparkplug.-----But you need to test the maximum output of the system.----So does spark jump a gap of 5/16" ( 8 mm ) or more , yes or no ?

Good question. I’m not sure how to test that. However, I will say the spark I was observing wasn’t exactly a STRONG spark. More of a “I think I saw a spark there”.
Perhaps the coil assembly could be bad? This may explain the blackish/wet plugs.
Is it common for the coil pack to go bad? How can I test this? Can I had a bad coil and still have a spark?
While this outboard is older. It’s in mostly pristine shape. And is only used for trolling (although, quick math estimates that at about 700hours)

 

[racerone]

A common fact most folks cannot comprehend.----Spark on a plug laying on the block may not be enuff to fire with the plug in a cylinder.----With 100 PSI compression you need more voltage.----Make a test device with 2 pieces of wire glued on cardboard.---With 5 /16" gap between them.