1978Johson 9.9 won't start after submersion

catbuster

Cadet
Joined
Feb 22, 2010
Messages
15
I'm lost. The motor was under water for 5 days in the river while i waited until it was low enough to chance retrieval. I let it sit for a while to let the electrical components dry out, hoping this would avoid frying something. I sprayed some starting fluid and nothing. I checked the spark and i'm getting 1/2" spark on the tester. I rebuilt the carb and still nothing! Could there be silt that has passed beyond the carb blocking the fuel? I used compressed air to blow into the intake when the carb was off and I had air coming to the plug holes as well as the fuel pump. Any ideas?
 

kbait

Commander
Joined
Nov 13, 2007
Messages
2,471
Re: 1978Johson 9.9 won't start after submersion

Ouch. You really need to get oil in there fast upon submersion. Hopefully, it's not too late.

First, squirt a bit of fuel mix in the plug holes, replace plugs and see it it'll fire/idle for a couple seconds. That would be a good sign. You may have leaf valves on the reed plate not seating if it'll run w/above test, but not w/spraying fuel in the carb. Starting fluid has no oil, so never use it for anything that requires mixed fuel!

Good luck.
 

V153

Lieutenant Commander
Joined
Apr 16, 2011
Messages
1,764
Re: 1978Johson 9.9 won't start after submersion

Well it was only under water for 5 days. Yikes! Though I've seen worse resurrected ...
 

boobie

Supreme Mariner
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Nov 5, 2009
Messages
20,826
Re: 1978Johson 9.9 won't start after submersion

What's the compression on it ?? Did you put new spark plugs in it ??
 

Jim311

Petty Officer 2nd Class
Joined
May 31, 2011
Messages
169
Re: 1978Johson 9.9 won't start after submersion

Mine took a day or so to dry out before it would restart. Are you using fresh fuel, not fuel from the tank that was submerged?
 

catbuster

Cadet
Joined
Feb 22, 2010
Messages
15
Re: 1978Johson 9.9 won't start after submersion

i put new plugs in. I'm using fresh fuel. After 78,469 pulls (give or take a few thousand), I'm getting a mild backfire when i pull the rope every 3 0r 4 pulls. I don't have many pulls left in me. Any ideas? I also checked the kill button to make sure there was no corrosion in the contact points. Have not checked the compression, but I put a mixture if gear oil and kerosene in the plug holes when i got it out of the water and let it set for several days while turning it over every day to keep oil coated on the cylinders. It never was "stuck" or hard to pull after i removed it from the drink. I pulled the inspection cover and there is no rust or corrosion on the pistons, rings, or cylinders that i can see. HELP!
 

AlTn

Commander
Joined
Mar 9, 2010
Messages
2,813
Re: 1978Johson 9.9 won't start after submersion

was it running when it went in the river?..possible you've sheared the crankshaft key?...if each plugwire is able to jump a 7/16" gap with a good blue spark, I'd rule out the ignition system and concentrate on the fuel side.

Is fuel mix from the fuel pump filling the carb bowl?...try hooking up a gravity fed fuel source ,or use the primer bulb to fill the carb bowl and test.

Have you tested the compression?
 

kbait

Commander
Joined
Nov 13, 2007
Messages
2,471
Re: 1978Johson 9.9 won't start after submersion

So.. did you try squirting a little premix in each plug hole, replacing plugs and test? Again, if it runs for a few seconds and dies-you have a fuel delivery issue. If not, you have inadequate compression, or it's sparking out of time (sheared key as noted above) or plugs aren't firing.
 
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