Intermittent engine stall-fuel flow issue

[cdennis]

I have a Suzuki 4 stroke that is 10 years old. It has been serviced and runs fine. However, it will stall periodically. The sequence goes as follows: squeeze primer bulb prior to starting, will start and run fine. Stop for awhile and then it will start up but stall within 2-3 minutes of starting. Squeeze the primer bulb and then it will run fine w/o stalling until the next time I stop. It seems there is a fuel flow issue. Hose from fuel filter to bulb have been replaced. Bulb is original. What would cause the fuel to seemingly be interrupted when I stop but always remedied by squeezing the primer bulb? What do I need to do to fix?

[Solarman]

I'd like to say, possibly a weak lp fuel thingy. Yes, that could cause that.

Do you realize that if I wanted to look up parts for your motor, there are a number of different 4 stroke motors made that year? Hello... You ask for help, can you help us on this side of the forum?

And why replace that one section of hose? Did it leak? The section you replaced from ”fuel filter to bulb”, are we talking fuel filter on motor, or fuel/ water separator filter to bulb? If one section leaked fuel, maybe some of the other sections will leak air, and make you need to pump bulb after stopping to fish?

Post back when able.

[cdennis]

Intermittent Stall Problem

Thanks for your reply. Apologize for lack of specs on engine. Was out of town and did not know but Engine is four stroke 140. Hose replaced was from external fuel filter/water separator. It was folded over and had major cracks. My mechanic mentioned the internal filter had a loose spring clamp that he thought might have been causing an air leak. He replaced that. Alas, problem still exists.

[Plane Fish N]

I have a Suzuki 4 stroke that is 10 years old. It has been serviced and runs fine. However, it will stall periodically. The sequence goes as follows: squeeze primer bulb prior to starting, will start and run fine. Stop for awhile and then it will start up but stall within 2-3 minutes of starting. Squeeze the primer bulb and then it will run fine w/o stalling until the next time I stop. It seems there is a fuel flow issue. Hose from fuel filter to bulb have been replaced. Bulb is original. What would cause the fuel to seemingly be interrupted when I stop but always remedied by squeezing the primer bulb? What do I need to do to fix?

Hey there,

I just bought a new 31 Twinvee with 250HP Suzuki's (engines were demos.. not registered with full warranty but had 280 hours on them). They also would operate fine until I stopped and shut down the engines. Once started, they would run fine for 2 or 3 minutes and then one and then the other (not in any particular order) would die and shutdown.

I would go back and pump the primer bulbs and then re-start and then, they operated fine!

The shop changed low PSI fuel pumps, put on new primer bulbs, changed fuel filters, psi checked the fuel tanks, etc. After going back and forth (45 minutes each way) to the factory for 6 different times, I was fed up.

They called Suzuki and ONLY then, did Suzuki admit they have a problem and no fix in sight.

Here is their theory:

Apparently, when I shut down the engines to fish or have lunch or whatever, the ethanol fuel (I'm not sure Ethanol Fuel has anything to do with it but it seemed that Suzuki was more adamant about the VST Tank) in the VST tank starts to vaporize and when you start the engine, there is enough fuel to run for a few minutes but then, the gases cause a "vapor lock" situation and shutdown.

Pumping the bulbs really doesn't do much except it gives the engines time to expel the gasses. Then, when I restart the engine, they will run fine until the very next time, etc etc etc.

I was very angry at Suzuki and if I could, I would have just gotten rid of the engines and bought Yamaha (yes, I have had 4 sets of Yamaha 4 strokes BUT THEY RAN!) Having had a set of Suzuki 150's prior (which I put 590 hours on) that were bulletproof, I decided to trade the 250's back in, pay thousands of dollars and had 2 brand new 300's installed and these engines are perfect!!! Problem solved. All it took was a lot of money.

I hope that you figure out your mystery and if you need any other info, just PM me.

Cheers

[Grumpy56]

I am new on this forum, so hopefully this reply will not violate any rules or protocols. I read about a vapor lock problem on Suzuki's somewhere on the Internet, apparently is occurs in hot weather. The answer to the problem appears to be installing a Low Pressure Electric fuel pump, between the fuel tank and the engine. This is from memory, so please check before implementing, the pressure should be set to 3 PSIG, and the pump should be wired to only work when the ignition is on. In one article they recommended this fuel pump: Carter P4389 - Carter Universal & Marine Electric Fuel Pump.

Hope it helps, and looking forward to being active on the forum,
Still Grumpy

[Moonlighter]

To the original poster:

About a year ago we had a problem with a mates DF300 where it would run fine but after a good run, when we slowed down to idle, it would stall. Sometimes even at the ramp when we started up and backed off the trailer, it would simply stall too. Pump the bulb up and it would be fine.

Turned out to the the anti-siphon valve on the tank. We got the tip from the Striper owners club and sure enough, we simply unscrewed the barb from the fuel tank, took it to the workbench, used a punch to punch out the ball and spring and the seat from inside, and reinstalled the barb and reattached the fuel line.

Problem solved. Never recurred.

It could be something as simple as that. I reckon there is a good chance this could the the problem on your boat too.

The anti-syphon valve is not required on outboard powered boats, so there is nothing to lose, and no expense involved, to get rig of it like we did. Give it a try and see what happens!

[Pleasureway97]

I also have a 2005 140 HP Suzuki OB and have been experiencing the same problem. I have changed out the water/fuel separator, hoses and bulb without any results in correcting the problem. One mechanic did state that using ethanol fuel may be causing a vapor problem, similar to another response. I continue to use a stabilizer additive but it doesn't seem to help with this problem that has been happening since new, but is much more consistent now. The boat manufacturer has stated that they do not put a check valve on the feed hose in the fuel tank. I don't know where to go next!

[Grumpy56]

Here is a thread that discussed the issue in 2011:

http://www.suzukioutboardforum.com/s...r-support.html