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2004 90hp Johnson, stalls under load

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steve6078

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new to the site any help is greatly appreciated, I have a 2004 Angler 18' boat with a 2004 90 Johnson, two stroke. engine ran fine two weeks ago, last weekend I took it out and when up on a plane it looses all power and stalls. no missing, engine doesn't stumble, actually seems like someone pulled back the throttle but it goes from 4500 rpm to zero. sometimes it restarts right away sometimes it take a few minutes, holding in the key (enrichener) it helps it to stay running. if i let it sit a few minutes it will start right up and rev to full rpm in neutral, if i go back in gear it will take off and then die. i hooked up a separate fuel line and tank direct to the filter no difference. now for testing i just back up in the ramp, leave it on the trailer and put it gear bring it to about 3000 rpm, in gear, it will hold it for a few minutes and then drop in rpm and die. fuel bulb stays full, doesn't collapse, filter looks new, engine has less then 150 hours, new plugs, fuel is getting to the bowl and to the hoses going to each carb. I thought it was a fuel problem now I'm not so sure. It doesn't miss, and no hesitation going on a plane, just runs for a few minutes under load and dies. in Neutral it will hold high rpm for ever. Any suggestions are appreciated.
 
Re: 2004 90 Johnson, stalls under load

I have 115 evinrude that is having the same issue. Just dies at 4200 rpm after a minute or so. Thought it was the fuel tank..ran aux tank same thing. Dealer told me it was the TPS sensor. Replaced that and same think happens. After a two hour water test with all equipment hooked up to motor it seems to be one of the fuel pumps even though fuel ball stays firm when stalling. Fuel pump can't keep up the pressure over 4k rpm. Will run all day under 4K. My engine is fuel injected.
 
Re: 2004 90 Johnson, stalls under load

If it's a VRO engine I would make sure your oil hose is not cracked. Your motor might be quitting due to lack of oil and you could end up ccoking your motor. Check all your hoses including those under the hood of your motor.
 
Re: 2004 90 Johnson, stalls under load

I'm going through the same think with my 115. After a two hour water test looks like one on the fuel pumps.
 
Re: 2004 90 Johnson, stalls under load

The fact that you can keep the engine running if you hold the key in which activates the fuel primer solenoid..... this indicates that fuel is available at the primer solenoid and carburetor area but is not flowing thru the carburetors.

This may possibly indicate a fuel restriction that would result in having the VRO (if so equipped) pump excessive oil into the carburetors. Note that I retired in 1991 from OMC so I am unaware if your engine has a vaccum switch that would sound an alarm when a fuel restriction is encountered or not. If not, this scenario is quite possible.

(Fuel Primer Solenoid Function)
(J. Reeves)

The RED lever...... The normal operating/running position is to have that red lever positioned over top of the solenoid and aimed at the other end of the solenoid, gently turned to its stop. This is the normal/automatic mode position. Pushing the key in opens the valve within the solenoid allowing fuel to pass thru it in order to prime and start the engine. Looking upon this solenoid as a electric choke results in a better understanding of it.

Having that red lever turned in the opposite direction, facing away from the solenoid, allows fuel to flow thru it to the crankcase area. One would only turn the red lever to this position in a case where the battery might go dead and the engine had to be started via the rope pull method. Look upon putting the red lever in this position as moving a choke lever on a choke equipped engine to the full closed position. Either one would supply fuel to the crankcase/engine for starting purposes BUT if left in that position while running would flood the engine.

The later model primer solenoids are equipped with a schrader valve, used for attaching a pressurized can of fogging oil etc, available at your local dealership with complete instructions.

Pumping the fuel primer bulb up hard fills the carburetor float chambers of course, but that process also applies fuel pressure to the primer solenoid.
The two small hoses leading from the primer solenoid branch off via tees to each fuel manifold section that would feed fuel to the individual cylinders.
Pushing the key in activates the primer solenoid to allow fuel to flow thru it to the intake manifold passageways. Cranking the engine over causes the fuel pump to engage which in turn sends fuel pulses to the primer solenoid via the 3/8" fuel hose.
Some engines incorporates the "Fast Start" feature which automatically advances the spark electronically so no advance of the throttle is required for starting.
Engines that do not have the "Fast Start" feature will be required to have the throttle advanced slightly.
Starting procedure: pump fuel bulb up hard, crank engine and push the key in at the same time. When the engine fires/starts, release the key so that it falls back to the run position.
Bottom line..... Look upon the primer solenoid as an electric choke.

(Fuel Anti Siphon Valve)
(J. Reeves)

Many of the later OMC V/6 engines incorporate a fuel restriction warning via a vacuum device attached to the powerhead. If the engine overheats, or if you have a fuel restriction, the warning is the same.... a steady constant beep.

NOTE... Only the V/6 & V/8 engines have the above "Fuel Restriction Warning". The warning horn will not sound on the other models.

The fact that a engine is not overheating, but the warning horn sounds off with a constant steady beep, and that the rpms drop drastically would indicate that the engine is starving for fuel due to a fuel restriction. Check the built in fuel tank where the rubber fuel line attaches to the tank fitting. That fitting is in all probability a "Anti Siphon" valve which is notorious for sticking in a semi closed position. It will be aluminum, about 2" long, and the insides of it will consist of a spring, a ball, and a ball seat. If this valve exists, remove it, knock out those inner components which will convert it to a straight through fitting, then re-install it. Hopefully that cures the problem.

The above procedure will cure a restriction problem with the anti siphon valve as stated. BUT, it may also allow fuel to drain backwards to the fuel tank when the engine is not running (siphoning backwards) due to the fact that the carburetors/fuel pump etc are higher than the fuel tank. This condition is not an absolute as the valves in the fuel primer bulb usually prevent this backwards siphoning problem. However.... if this does take place, the cure would be to install a new anti siphon valve.
 
Re: 2004 90 Johnson, stalls under load

thanks, yes it does have the VRO, has an alarm and idiot light that come on when i turn the key but go off as soon as the engine starts. Holding the key in will keep it running in neutral or at low idle on gear. I checked gas to the carbs, but not through them. As it has four carbs I just figured the engine would run but stumble if one or two dropped out. But your point is good if too much oil gets in they could all foul and that would explain why when it stalls it takes time to start and that the solenoid helps by allowing more fuel in. The books says the engine will simply alarm but keep running if oil circuit fails (of course the engine could be damaged) So do you think the fuel pump is failing and allowing too much oil in(not enough gas) and also do you agree that it should stumble if one or two carbs fouled. Everything I have checked looks brand new, filter, float, oil and gas lines as well as pump diaphram. One other note the oil tank bulb since day one has always been hard as a rock, even after the winter it is rock hard in the spring but does use oil that i would expect. thoughts?? Thanks
 
Re: 2004 90 Johnson, stalls under load

The oil bulb always stays very hard.

Simple to check the carbs. Simply remove the screw/bolt plug from the front bottom portion of the carburetors. If excessive oil, it'll be right there.
 
Re: 2004 90 Johnson, stalls under load

well finally got some time off and checked the carbs after it stalled, NO excessive oil BUT found water. Drained the tank, I had just put 30 gallons in a 33 gallon tank and found about 4 gallons of water in the gas. When I used the remote tank I simply used the primer bulb and line to the boat tank to fill a smaller tank (I was thinking restriction not water)

I had rags under the carbs and when I let them drain there just wasn't a strong smell of gas.

I have not load tested but hopefully this is the problem. Seems the local gas station was sucking the bottom of the tank when I filled up. As mentioned before it never had the slight problem before this day, the weekend before she ran like a top.

I'll confirm the fix on Friday and report back.

Joe R. thanks for your help, your direction pointed me to the problem, thanks to all who commented. I have installed a separator in the fuel line, did some other maintenance as well.
 
Re: 2004 90 Johnson, stalls under load

OK finally tested the boat and same thing happened. Still seems like a fuel issue and still see water in the carbs, also the gas doesn't have a strong odor and seems very oily. I started thinking it was diesel. Anyway I decided to remove all the gas from the tank and after filling six 5 gallon buckets I found more water. I let the buckets sit overnight and it was clear i have water getting in my fuel. I sealed the fill and vent on the tank, hooked up a pressure gauge setup on the fuel line and tried to apply air pressure. I could hear a leak, I pulled the access panel at both ends of the tank and found air coming from the fill end. I thought it was a hose but after cutting out a section of the floor panel I found holes in the fuel tank. The aluminum tank had four holes that look like pit marks / corrosion, the rest of the tank looks fine. I ground it down, washed with solvent and applied Marine-tec epoxy. Now the tank holds pressure, I applied 2 psi and it held for an hour. The way the tank was installed lets water sit on top at this end, the foam the factory installed created a perfect area for water to pool. I took the boat out and ran for about four hours with no issue.
 
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