Suzuki DF 250 stalling when idling??

[Letsfish9]

Thanks for all the help. Yesterday i ran a 5hr charter. I keep my boat on a lift and leave to meet the live bait boat on the water around 5:30 am. We meet at the public boat ramp which is about 3 miles by water. He smelled fuel when i restarted the engine . I checked the fuel connections of the water seperator filter and primer bulb with a flashlight, looked dry. I have noticed a slight fuel smell when starting the engine on occasion .i have not seen any sighn of fuel in the water. With the cowling off, i have not seen any fuel leaks, drips or anything when starting the engine. I ran the motor on the trailer at home Sunday with the cowling off. I ran it at idle for 1hr and 15 minutes continusely , no visible fuel leaks on the boat lines or on the motor. I thought i had corrected the problem since it did no shut down. Tues, the motor ran fine all morning, at times, idling for 10 to 30 minutes. I stopped on the way back home after a 5hr charter, to fish some live baits i still had. After 30 minutes i started the motor, idled fo 10 minutes, got on plane and the engine sshut down after after 5 minutes . Pumped the primer ball ,felt fuel going thru, turned ignition key on a couple times then was able to restart engine. Ran 5 minutes home ok.
This was how my day went. This was a little different than usual since

the engine usually shuts down after idling for 1/2hr +.
last night i removed the fuel line from the primer bulb to the engine. There is a connection inside the rigging tube to a preformed engine fuel line going to the 1st fuel filter on the motor. I plugged one end of the line and applied air pressure withe it in the swimming pool, no leaks and looks fine. I will replace this fuel line today and continue looking for answers. So, i have replaced the tank pickup and every thing to the engine itself. Double checked all connections.

[artdf175]

I found my problem when running at home with the cowling off
watch the small filter on the fuel line before the low pressure fuel pump..
watch for air bubbles-- there should be no air getting into that filter ,..
another thing that has not been mentioned is the IAC valve.
Has that been cleaned recently.. often creates problems with idling correctly if it is dirty

Art

[Moonlighter]

How many hours on this engine?

[Moonlighter]

Any update?

[Letsfish9]

1550 hrs on the engine. New fuel line to motor added. A mobile suzuki mechanic was supposed to to check out but said he is buried for a week. It has been 2 weeks and now he doesnt respond to msgs or voice mail. I was out of town for a week but he has access to boat and i am a phone ccall away. He can come any time. Frustrating, i make it very easy but no reply. Looks like i will belooking at the vst today. Any advice will be appreciated.

[Murray]

If it was me tearing apart the VST I would want a Suzuki genuine service manual. S e l f f i x e r d o t c o m (all one word) might have a pdf for your engine depending upon the year of your engine.

[artdf175]

You have a fuel starvation problem..
It is doubtful it is the Vst- high pressure fuel pump is the problem - or it would show up when running the RPM' at a higher than idle speed
It doesn't hurt to either drain it (screw on the bottom side) to check for water or open it and again lol for water / debris
but again I don't thing that is your problem.

The fuel is either restricted or you have a leak in the fuel line allowing air to be sucked into it. The latter- the VST runs out of fuel and the engine quits
you can remove to fuel hose from the low pressure pump and run a hose off it to a container and turn the engine over to be sure the low pressure pump is working correctly.
visually check the inline fuel filter for air getting in while runnng the engine, there should be no air in it.
and lastly the fuel tank breather.

Have you tried to run on a spare portable fuel tank??
Art

[Moonlighter]

In addition to the suggestions above, I would check when the hp fuel filter (the black expensive one) was last replaced, I think they are due every 400 hours or something like that.

While looking at those records, find when the valve clearances were last checked. If not done, get that done too. If any valve clearances are out then a special tool is required plus shims. Suzuki mechanic should have that stuff, if they are any good.

[Triton2300]

Try disconnecting the fuel line and running a separate fuel line and portable tank. If it runs okay you have isolated the problem to be outside the engine.

[Letsfish9]

Murray, I drained the VST. No water or trash. I have the service manual so i removed the VST. The filter on the high pressure fuel pump is clean. The float adjustment is correct. The pressure regulator releases at 36-38 lbs.
MOONLIGHTER, The high pressure filter was replaced previously during troubleshooting. The valve clearances have not been checked. Can this cause my problem? The motor runs perfect except for shutting down during a long idle period.
Artd175 thefuel tank breather(vent hose) is clear . I will test the low pressure fuel pump like you said today. Also i will check for bubbles in the inline fuel filter.
REMEMBER, this is a intermittent problem. The first time it happened was over 6 months ago. It has gradually gotten worse but may not act up for several trips. I have thought i finally corrected the problem only to have it resurface again..

[Letsfish9]

So far, 3 trips and running good.

[Letsfish9]

After today, going to have knee surgery so about 3 weeks till i run the boat again. Will post after i am on the water again.

[Letsfish9]

Took the boat to an authorized Suzuki dealer while my knee is mending. He said a pick up sensor under the flywheel was the prpblem $400. Later, i picked up the boat and went straight to the launch ramp. You guessed it, same problem. Ran fine for acouple hrs then wile idling thru a 20 minute no wake zone it shut off like b4. Primed the ball , switched ignition off and on a few times, engine started and ran fine back to ramp, about 15 min. Part idle and part running 3k rpm. Went straight back to the dealer and left it. He has had it for another week, still waiting. Ugh!

[Letsfish9]

Had the technician ride with me. We idled around, stopped and started a couple times and after 2 hrs with no problem , i took it home. Used the boat the next day, it ran fine. The following day ran around for 1/2 hr then idled thru a no wake zone, about 10-15 minutes and the engine shut off. Primed the ball and it started up fine and ran 10 minutes with another 5min idle, ran home on a plane about 10 min, ok. It never shuts down while running, only while idling for a while and will not start until i pump the ball several times.
i need help!

[Jaybord]

Letsfish9 any luck on this issue?