Engine is stalling out after planing out.

Help!!
I have a 1996 150 hp Johnson fast strike V6 mod#J150GLEDB. I bought this boat very early spring of 2019 and it ran like a champ. I had it on the lake many times and it done great! One evening after fishing I was returning to the dock and it died. I was at full throttle and it was like it ran out of gas. I changed tanks with the valve, reprimed with the bulb and the engine would not take any throttle. Tried to reprime several times and the only thing I could get was an idle in gear. To make this short I will list what has been done to this point. The carbs were rebuilt just before I bought it, (My brother had it done) changed the priming bulb, changed all of the gas lines from tank to engine, checked down tubes in tank, screens where clear, changed fuel water filter, changed gaskets at sending units, VRO was disconnected so I replaced it with a fuel pump without VRO, changed needle valve and seat, replaced float, checked compression (was within tolerances), checked spark good, changed spark plugs (old ones where in good shape). I think that was it. That is not the order I did all of this! I mix the gas since the VRO disconnected. I would take the boat out after doing some of the repairs and it would do the same thing. After replacing the fuel pump I took it out and it ran good at idle and it would throttle up and right after planing out (about 30 seconds) it would start to die like it was running out of fuel. I would reprime it and it would do the same thing.
Can you help with this I don't have much hair left!
Greg

Is the bulb getting sucked flat when this happens? If so you likely have a fuel restriction either in the tank vent or anti-siphon valves (if your tanks has one). You mentioned a fuel selector switch so I assume you have dual tanks. It's possible you either have a restriction at the selector switch. Maybe a piece of gunk is blocking it or a gasket or O-ring has deformed.

The easiest thing is to get an external fuel tank, connect that to engine and take it for a run. If all is good on the external tank then you know the issue is somewhere between the primer bulb and the tank(s). If it behaves the same on the external tank then you have a restriction somewhere at the engine.

The bulb is not getting sucked flat but it does loose its prime. I can pump it back up and it will do the same thing. I remove the selector switch and check and cleaned and it was good. The vents tubes are clear and I do not have anti-siphon valves.

I will hook up an external tank and let you know what happens.Thanks for the quick response!!
Greg

A freak thing that happens from time to time............

Due to someone failing to replace the clamp cover over the adjustable trunions of the control cables.... the throttle cable will pop out of its retaining clamp slot.

ggrdoghouse said:

The bulb is not getting sucked flat but it does loose its prime. I can pump it back up and it will do the same thing. I remove the selector switch and check and cleaned and it was good. The vents tubes are clear and I do not have anti-siphon valves.

I will hook up an external tank and let you know what happens.Thanks for the quick response!!
Greg

Click to expand...

Okay, looks like you've covered a lot of bases. If you're losing prime then it sounds like you have an air leak somewhere.

Just for grins, remove the primer bulb and test it for suction. You should be able to put your finger over the inlet then squeeze and feel suction. My guess is that side is good since you said it will draw fuel. The more important test is to squeeze it flat then place your finger over the outlet. While keeping your finger in place release the bulb. You should feel suction against your finger and the bulb should stay flat. If that does not happen then you have a bad bulb and fuel is flowing back into the tank.

Another possibility is you have a bad fuel pump or a bad connection to the cylinder for vacuum pulse and you're not drawing enough fuel volume to keep the carbs filled.

You say in your Post #1: " After replacing the fuel pump I took it out and it ran good at idle and it would throttle up and right after planing out (about 30 seconds) it would start to die like it was running out of fuel. I would re-prime it and it would do the same thing" ... You also state that the Fuel Primer Bulb Does Not go flat.

If a fuel restriction existed, that fuel primer bulb would surely go flat... and also on that model you would receive a warning horn sounding identical to a overheat warning (Constant Steady Beeeeeep). Your warning horn does work, does it not?

Your wording indicates that you have more than one built in fuel tank... and both without "Anti Siphon Valves".<-- This setup, since the tanks are obviously lower than the engine would allow fuel to siphon backwards into the tanks when the engine is shut down which sets up the scenario of having air in the lines.

I strongly advise installing new Anti Siphon Valves in the tanks right at the fuel outlet where the fuel lines can connect directly to them.

Your explanation also coincides with a tank or tanks that are nowhere near full that would have a flaw in the pickup line within the tank whereas a hole would exist (some kind of leakage) when throttle is applied... and the fuel would flow away from the pickup, allowing that flaw to reveal itself to result in the problem you describe.

The only remaining problem that comes to mind at the moment would be one hellava air leak in your fuel system somewhere... BUT... if that existed, by the same token, you would have one hellava fuel leak that you and everyone else nearby would be smelling immediately (Not likely!).

There is no mention of water pump maintenance.-------Is motor going into " S.L.O.W. " mode here ?------What are those " good " compression readings ?----Fuel pump is driven by PRESSURE pulses from the crankcase.------Have you looked into pulse issues there ?

Hey all of these ideas sounds great. We have had a family emergency so it may be a couple of days before I can try these things.

Ok im back.
I have checked the primer bulb and it worked fine but I went ahead and bought a new one made sure it worked and installed it. I needed a spare anyway.
I hooked up an external fuel tank and it did the same thing.
Someone had mentioned gas in the tanks, they are full.
The compression on the cylinders where 88, 88, 90, 84, 85, 85.
The only alarm I had ever heard is when I turn the key on, there is a beep.
There was mention of pulse issues. How do you check that?
There is one thing that its doing that I didn't mention. If I run it out of the water it will run about 2 minutes and it starts running out of gas. I can pump the bulb and it will start running smooth again for about 2 minutes same cycle. I tried something that hasn't been mentioned. I removed the priming bulb, put a coupling in and extended the fuel line, mixed some gas in a gas can then primed the extra fuel line and sat the gas can higher than the carbs and it ran great. I don't know if that helps out.

The last line of your #9 post states..." I removed the priming bulb, put a coupling in and extended the fuel line, mixed some gas in a gas can then primed the extra fuel line and sat the gas can higher than the carbs and it ran great. I don't know if that helps out."

What would happen with that gas can lower than the carburetors?

the engine would run for about 2 minutes and start to die

Sounds like the fuel pump is not working as designed.-------Should be easy to trouble shoot.-----Pulse limiter still in the system ?

That sounds to me like your fuel pump isn't working, but you said you just replaced it. Keeping the gas can higher than the carb helps bypass a bad fuel pump by making the fuel flow with a gravity feed.

Yes the pluse limiter is still in the system.

What fuel pump part # did you install.----The pulse limiter is a " flow fuse " to protect the VRO pump that you removed from your motor..

part # FP-5007422. It came with a pulse limiter that I installed.

Pulse limiter is required for that pump.

I am not familiar with a pulse limiter. Could there be a blockage before the pulse limiter? If so how can I check it?

The pulse limiter is a flow fuse.-----It closes when too much air goes through it.-----Protects the big PLASTIC housings from going " BOOM " due to a pressure spike.-----There may be issues with positive pressure pulses that drive the pump.

Here are some pictures

I was going sending pictures but couldn't figure it out.
I checked a few more things out. I pulled the vacuum pulse hose off that runs from bottom of crankcase to the fuel pump and it is pulsing. I pulled the hose that runs from the top of the crankcase to the vapor pump and it is pulsing. Is there a certain pressure that it should be pulsing at? if so how do you check that? As I was doing this the engine died so I pumped the bulb and I heard air that sounded like it was coming out of the vapor pump. As soon as the bulb started getting firm it quit. Is the normal? Also I noticed that there was a lot of air going through the fuel system. Someone had mentioned about anti siphon valves could that cause fuel not to flow good during operation? Where can I get them? I also checked the recirculation hoses for cracks or hardness and they were good.

Either top of fuel bracket leaking, plastic fuel line on cowling cacked or VRO air motor is bad. The vapor seperator(VS) is filled when you pump bulb, the VRO pulls fuel from chamber and delivers it back to carbs thru the VS in a different passage. The VS has to be 100% sealed or the VRO cannot pull fuel from system. If any air leaks it will use what fuel is in chamber and then it will run out of fuel requiring a reprime of system from bulb.

I replaced float, needle and seat, o rings, gaskets except for one that I could not find. It goes in between the lower body and the intermediate body of the vapor separator. I called Marine Engine and they said that it was not available so I used the old one. I think that's where the air is coming from when I pump the bulb. Do you know where I can get one? I hope that is it!

If it is 335236 it shows they have 10 in stock.-------Every factory dealer will likely have it in stock too.

Ok I fixed it by the process of elimination. I had replaced every gasket, o'ring, needle and seat, fuel line, fuel filter, vacuum line, plugs and fuel pump except for the one gasket no one could seem to have. I could not see anything wrong with it but it was as hard as a rock. I went to the local auto parts and purchased gasket material and made one myself. it now runs like a champ. The only thing is that it has a small miss every once in a while. I can live with that for now. I tried to download pictures but for some reason the system would not let me. If you want to see what gasket I was talking about look in repair book Seloc Johnson/Evinrude All V4, V6 and V8 Outboards 1992-01 18-01331 fuel system 3-39 Fig. 137 gasket in between intermediate body and lower body.
Thanks for everyone's help!!