1989 Foce 50 HP - Running perfect, then stalled. Will not restart and backfiring

[httysctty]

I have a 507Y9B that I have pretty much rebuilt due to numerous issues. This is my first boat and many of you have really helped me learn about ouboards, thank you. It is on a 1976 aluminum v-hull and I put a center console on it. I finally got her running perfect and was loving the ride. Used SeaFoam in the gas and ran fine for 2 hours at low RPM. I dropped my wife off at the dock and cruised @ WOT. Then she started making "funny sounds" and died. Tried starting her up and nothing but an occasional backfire:facepalm:. The backfire is coming from the exaust. I did use 5 month old gas that I had for my lawnmower. Any ideas? Reed valve? I would love to get back out before it gets cold. Thanks in advance.

 

[jerryjerry05]

Re: 1989 Foce 50 HP - Running perfect, then stalled. Will not restart and backfiring

First I'd check the gas for water.You did mix oil with the gas??Seafoam is good for cleaning carbon and you can use too much.
Then I'd do a compression/spark test.
Under the flywheel is a magnet.It might have come loose.Or the flywheel key sheared.
Then check the fuel pump diaphram.J

 

[httysctty]

Re: 1989 Foce 50 HP - Running perfect, then stalled. Will not restart and backfiring

Thanks for the reply. I think the gas is fine, but I may have used a little too much sea foam. Magent is good (visually), but I am now leaning towards flywheel key... Do I need to worry about the pistons? I will start looking into testing compression and spark... if I can figure out how to test. =)

 

[jerryjerry05]

Re: 1989 Foce 50 HP - Running perfect, then stalled. Will not restart and backfiring

Get a good guage.It's something that will last a long time.Mines over 20yrs old.
It's the first step in diagnosing an outboards problems.
When you get it.Remove both plugs,open the throttle all the way and use a jumper to turn the motor over.Let it spin till the comp stops going up.Do it twice.J

 

[httysctty]

Re: 1989 Foce 50 HP - Running perfect, then stalled. Will not restart and backfiring

Well, I have not been able to get a guage yet, but I pulled of the flywheel and found this. Is it sheared?View attachment 113307

 

[jerryjerry05]

Re: 1989 Foce 50 HP - Running perfect, then stalled. Will not restart and backfiring

No pic.Sent U a PM