motor totally kills when accellerating

[h0tr0d]

Hopefully someone can help me with my problem.

I have a 150 evenrude 60 deg and the motor totally shuts down when under heavy acceleration. I pulled the gas tank and drained it, put fresh gas and oil in it and still the same problem. It is still easy to start and will idle all day long, but as soon as I get on plain and even out it shuts down. Then it is hard to start (pump the bulb and try a few times). Anyone ever heard of this? I am going to wait to give my theories.

 

[Theoutdoorsman]

Re: motor totally kills when accellerating

Sounds like it's starved for fuel to me. It might be time to clean the carbs. But before you do, you might consider elaborating on the "squeezing of the ball" a little. You might have other issues. Does the ball go flat? Is that why you have to squeeze it to re-start?

 

[jtexas]

Re: motor totally kills when accellerating

welcome to the forum.

VRO or premix?
Choke plates or primer?

Is it bogging, like it wants to go but just can't, or does advancing the throttle shut it down, as if you turned the key off?

How old was the fuel you drained?

Can you make it run by pumping the primer bulb when it starts to bog down?

Does the fuel line hold pressure with the engine not running?

 

[h0tr0d]

Re: motor totally kills when accellerating

Thanks for responding. Yes the ball goes flat. The ball never did get rock hard before when I primed it. It is now premix I removed the vro about 4 years ago. It doesn’t bog down it totally shuts off like I turned the key, and power is great until that happens. The fuel I drained was only two months old but I drained it anyway.

 

[jtexas]

Re: motor totally kills when accellerating

Prime suspect is the fuel pump. Be curious to know whether the carb bowls are full after it cuts off. Not sure about that model, whether a punctured diaphram can leak into the vacuum line. I'd inspect all the fuel lines & fittings, consider replacing the bulb if it's more than a few years old.

 

[h0tr0d]

Re: motor totally kills when accellerating

Thanks. I’ll start there and report back in.

 

[ezeke]

Re: motor totally kills when accellerating

If the flattened bulb is before the pump, the problem probably is too.

I would suspect the anti-siphon valve at the fuel tank. It is located in the connector for the fuel hose at the tank.

Also, make sure the screen on the tank vent is clear.

 

[jtexas]

Re: motor totally kills when accellerating

when you say "goes flat" I took it to mean lost pressure...if it's actually being sucked flat then the pump's gotta be pumping

 

[h0tr0d]

Re: motor totally kills when accellerating

I am starting to suspect the carbs. I replaced the fuel line from the tank to the engine case and the bulb and that helped I guess. Now when it shuts down, if I back off the throttle real fast the motor picks back up and keeps running.

 

[jtexas]

Re: motor totally kills when accellerating

Reason I suggested fuel pump is, that your problem affects all cylinders. If pumping the primer bulb when it starts to shut down helps it at all, that would indicate fuel pump.

Another possibility is got a wiring fault that is affected by the throttle movement...chafed insulation or something. Coincidental to your fuel pressure issue of course. See if you can kill the engine by jiggling the wires off the timer base while it's idling.

 

[h0tr0d]

Re: motor totally kills when accellerating

mechanic said its the ignition system and about 900 bucks to fix. i am going to get a breakdown and see if its something i can replace myself.

 

[clint]

Motor totally kills when accellerating

Motor totally kills when accellerating

Sounds like a fuel problem to me. Rebuild your fuel pump. Also air could be seeping in from loose fuel line connection or primer bulb is shot. Also if you havent done a carb rebuild in a few years, it could be time to do so. I have a 140 Evinrude and had the same exact problem. I replaced my fuel pump all the old fuel lines, a new primer bulb. All for under $100.00. Check all wire connections and clean all your ground leads. Good Luck!
Clint 8)

 

[jtexas]

Re: motor totally kills when accellerating

hotrod,
If your mechanic determined that it's losing spark on acceleration, then you'll just be spinning your wheels trying to chase down a fuel problem.

If your problem is in the ignition, you can fix it - you'll need a repair manual.

Here's a handy ignition system trouble-shooting guide:
http://rapair.com/Portals/0/downloads/TroubleshootingGuide.pdf

 

[sport300zx]

Re: motor totally kills when accellerating

I have a 89' 120 v4 that does the same thing only it wont start back after it dies, so i turn the the power of then it cranks back up later and the primer bulb is staying primed.

 

[drJ]

Re: motor totally kills when accellerating

We have a 200 hp Johnson and it had a similar problem. It would idle fine but when accelerating it would loose power and sometimes cut out. The dash warning check engine would sound too. Our primer bulb would also go flat. It ended up being a piece of sediment stuck in the tank pickup line. After we removed it the engine ran fine. The blockage caused the fuel pump to create a vacuum causing the bulb to be sucked flat.

 

[skynyrdcat]

Re: motor totally kills when accellerating

We have a 200 hp Johnson and it had a similar problem. It would idle fine but when accelerating it would loose power and sometimes cut out. The dash warning check engine would sound too. Our primer bulb would also go flat. It ended up being a piece of sediment stuck in the tank pickup line. After we removed it the engine ran fine. The blockage caused the fuel pump to create a vacuum causing the bulb to be sucked flat.

Also had a similar problem and it was the connection between the fule line and the engine (drawing air).

 

[Jason Edwards]

Re: motor totally kills when accellerating

If the ball goes flat I wouldn't think that you have a bad connection. If a hose or fitting was pulling air then the primer bulb would not go flat. I had the same problem with my center console with a 200 Johnson Oceanrunner. It was hard starting when cold and if the engine didn't die on plane then the check engine light would come on and indicate a fuel restriction. Someone from an iboats forum suggested I look at the anti-siphon valve. It took me a couple of hours and $0 to fix. As it turned out it was a stuck anti-siphon valve which was preventing the correct amount of fuel to be pumped into the engine. I merely took off the anti-siphon valve and knocked the valve out with a hammer and punch. I was also told that if I had a good primer bulb that it would prevent the backflow of fuel into the fuel tank. Ever since I removed the anti-siphon valve it runs like a champ. FWIW

 

[Jason Edwards]

Re: motor totally kills when accellerating

Hotrod, according to your post #4 I would bet the anti-siphon is your culprit. My anti-siphon valve NEVER got hard until I took out the valve.

 

[wetdrive]

Re: motor totally kills when accellerating

I had the same problem on my 115 merc. I pulled the check valve out of the top of the gas tank where the gas line is conected. I took a punch and knocked the ball bearing and spring out and re installed it. (there is already a check valve in the primer bulb so you don't need one at the tank). To double check have someone drive your boat and when it starts dying on accellerating pump the bulb a few times. If performance improves it is likely the check valve sticking.

 

[sport300zx]

Re: motor totally kills when accellerating

Turned out to be the power pack. but i also had a leak in my fuel lines to all is replaced and all is well. thanks a lot everyone!