2001 Johnson 90HP Dies on the water

[jsonnebe]

I bought a pontoon recently. It came equipped with a 2001 Johnson 90 HP (J90PLSIG). It ran in the previous owner's driveway.

I went to start it for the first time in my driveway, and it fired up for three seconds, but died. We could not restart it.

A couple days later, it started right up in my driveway and ran fine. Stopped and started several times with no issues. Took it to the lake and it was hard to start, but it pushed the pontoon along OK. Top end seemed like it lacked power. Less than 10 minutes into the ride, the motor slowly lost power and died. Like someone did it on purpose, slowly throttling down to nothing. It would not start back up on the water.

A couple of days later it ran great in my driveway again. Started and stopped several times with no issues. Took it to the lake with similar results as before, only the motor didn't last as long before it died.

Things I did to troubleshoot: Drained the tank (plastic) and filled with fresh gas. Replaced the fuel line with a new setup - from the tank to the motor. New spark plugs. Pulled the gas cap during issues with no change. Squeezed old and new primer bulb during issues with no change. It sounds like a fuel issue, but I am at a loss as to why it wont start back up or stay running on the water?

I don't have much experience with outboards, so I am at a loss. Can someone point me in the right direction? Thanks.

 

[racerone]

Mixing gas and oil at 50:1 in the tank?-----Or if running with automatic injection is it in service and tested?----Water pump impeller replaced?

 

[jsonnebe]

Mixing gas and oil at 50:1 in the tank?-----Or if running with automatic injection is it in service and tested?----Water pump impeller replaced?

Running with automatic injection. I have both an idiot light and an alarm installed. the gauge and alarm are fully functional and have not alerted to any trouble. Have not replaced impeller yet, but strong flow out of the telltale.

 

[saltchuckmatt]

Compression check is in order....and so are temp readings. IR guns are inexpensive. Things could be shutting down when they get warm so take a timing light with you next time and see if your still sparking.

 

[jsonnebe]

Compression check is in order....and so are temp readings. IR guns are inexpensive. Things could be shutting down when they get warm so take a timing light with you next time and see if your still sparking.

Compression is between 105 and 110 across cylinders. After our dies on the water it will occasionally fire and sputter for a second or two. I have a temp warning light that functions. No indication of overheating.

 

[racerone]

Are you pushing the key in and holding it in while cranking it over?-----And careful with excessive cranking as starter will be destroyed.

 

[jsonnebe]

Are you pushing the key in and holding it in while cranking it over?-----And careful with excessive cranking as starter will be destroyed.

In the driveway, it starts without much fuss (except for that first time). On the water, after it dies, we try all variations of cranking. We don't hold it over for extended periods, but we have tried multiple key-push-in-scenarios.

 

[racerone]

Test the electric primer valve.----Does it click when you push in the key?

 

[jsonnebe]

Test the electric primer valve.----Does it click when you push in the key?

Yes, the primer valve operates with pressing in the key.

 

[Berdink]

When my Suzuki was doing something similar, it wasn't getting enough fuel. Enough for running in the driveway, but not for sustained use under the load of pushing the boat.
Mine was the primer bulb. I had the issue with two primer bulb hose setups.
So I bought, I think, a Sierra Marine primer bulb and that fixed it.

 

[ranger335]

Before I did anything else, I'd check the screen in the fuel pump.

 

[jsonnebe]

When my Suzuki was doing something similar, it wasn't getting enough fuel. Enough for running in the driveway, but not for sustained use under the load of pushing the boat.
Mine was the primer bulb. I had the issue with two primer bulb hose setups.
So I bought, I think, a Sierra Marine primer bulb and that fixed it.

I'm thinking fuel also, but I can't explain why it won't start back up on the water. If it was simply not getting enough fuel, wouldn't you think a 15 minute rest and it should fire right back up like it was in my driveway? That has me stumped.

 

[jsonnebe]

Before I did anything else, I'd check the screen in the fuel pump.

I think that's my next move. But the fuel pump is a bit buried, at least to my rookie eyes. Wish me luck.

 

[ranger335]

I've never seen it with an outboard but it makes sense that at higher RPMs the fuel consumption is greater and the trash clogs the strainer faster. Then, after a sit, the debris settles out, and we can go again, for a while.

 

[Mc Tool]

I've never seen it with an outboard but it makes sense that at higher RPMs the fuel consumption is greater and the trash clogs the strainer faster. Then, after a sit, the debris settles out, and we can go again, for a while.

Been there , very possible especially if the fuel line is going uphill before strainer.
Mine was in-line fuel filter disintegrating and particles of paper element being carried up to strainer by fuel flow ....engine stops .... blockage particles sink back down fuel line ....motor runs ....rinse and repeat

 

[Crosbyman]

any grey hose used here... inside plastic liner is known to deteriorate and impeed fuel flow.