Suzuki DF 9.9 runs then not

[lestersails]

I wonder if you outboard wizards can direct me to a fix. I have 2015 Suzuki 4 cycle 9.9 (same as 15 and 20 horse models) as an auxiliary. Fuel injected. Before running it the first time, I replaced plugs, upper and lower oil, oil filter, fuel filter, impeller, and tank to engine fuel line and bulb. Had a dealer replace timing belt. Fuel tank was emptied and dried. Filled with fresh ethanol-free gas and added recommended amount of stabilizer. Bought a cheap little fuel pump and filter and clarified the fuel for several hours (~25 gal/hr pump). There was a little bit of black debris in tank, so I wanted to try to clear that, even if engine fuel filter and sieve in tank inlet should make that not a problem.
First trip out she started up quite easily. Ran for 10-15 minutes pretty well, but felt like when I throttled her up, she bogged a little. Then she died. Fortunately, by that time I was to the river inlet and could sail her, we had a nice afternoon of sailing, then headed back. Winds were favorable to sailing her nearly all the way up the river and creek to the marina. Was able to re start it. Was not idling great (died at low idle), but ran well enough and long enough to get her back on the trailer.

I have looked at a couple YouTubes on similar issues. TBH, I wasn't all that confident that those were a good source of info. What do you folks think? Does this sound like water or other gunk in fuel system upstream of engine filter? Is my next move to remove and clean fuel pump and injectors? I was inclined to just go ahead and replace them, but a pump and two injectors would cost ~$600!

[GreenWave]

I’d run some fuel injector cleaner through it as very high concentration at least hAlf gallon of gas worth.

[Rumrace]

There could be a tear in the inner fuel pump membrane or the neutral ground shift switch is shorting.

[Stu Jackson]

Originally Posted by Rumrace

There could be a tear in the inner fuel pump membrane or the neutral ground shift switch is shorting.

Good, or the kill switch wiring is snafued. Happened to me once.

[lestersails]

Originally Posted by Rumrace

There could be a tear in the inner fuel pump membrane or the neutral ground shift switch is shorting.

Is this the switch that prevents the engine starting if it is in Forward or Reverse?

[lestersails]

Originally Posted by GreenWave

I’d run some fuel injector cleaner through it as very high concentration at least hAlf gallon of gas worth.

Will do!

[lestersails]

Originally Posted by Rumrace

There could be a tear in the inner fuel pump membrane or the neutral ground shift switch is shorting.

I am partial to your first suggestion over the second - something fuelish feels right with respect to the fact that when I throttled up, it bogged down and would not rev high. Electrical would be either running perfect or kaput, right?

[Rumrace]

When you shift gears a small micro switch with a long arm grounds the power to the spark plugs to protect the clutch.
They key bent mucking around with motors and do wear out.

The fuel pump has 2 thin membranes on either side of the metering block. When the inner one rips the motor will run like it’s starving for fuel and stumble returning to idle.

[Redpcx]

The squeeze bulb in the fuel line can be used as a diagnostic tool, and an emergency (low pressure side) fuel pump.
With the engine running, squeeze the bulb which will push fuel through the fuel pump into the injector pump ( or carb on older engines).
If the bulb stays flat, it can’t suck either a clog or clogged filter.
Filters CAN clog faster than you would believe.
AND REMEMBER!! Water won’t burn.

[Mike Banks]

Sounds like either a fuel pump and/or a weak coil. Oh--and check the air hole in the fuel cap.

[Captain Bill]

You can buy a Suzuki diagnostic cable and software online for well less than $100. I bought it for my 15hp. It will tell you exactly why the engine shut down. It took a bit of effort to get the USB port set up as a comm port on the laptop but it was well worth it. The onboard diagnostics are very good if you can get at them, but that takes a cable and the software. Why spend a lot of time and money shooting in the dark. Unlike some other brands that sell their diagnostic stuff for big bucks, Suzuki's is available relatively inexpensively.

[lestersails]

Originally Posted by Rumrace

When you shift gears a small micro switch with a long arm grounds the power to the spark plugs to protect the clutch.
They key bent mucking around with motors and do wear out.

The fuel pump has 2 thin membranes on either side of the metering block. When the inner one rips the motor will run like it’s starving for fuel and stumble returning to idle.

Thanks! And these membranes and tears can just be directly visually assessed or is there any trick to that?

[lestersails]

Originally Posted by Mike Banks

Sounds like either a fuel pump and/or a weak coil. Oh--and check the air hole in the fuel cap.

Did not think of coil, your fuel pump recommendation aligns with other. I definitely checked the air hole in the fuel cap - definitely open. Thanks!

[lestersails]

Originally Posted by Captain Bill

You can buy a Suzuki diagnostic cable and software online for well less than $100. I bought it for my 15hp. It will tell you exactly why the engine shut down. It took a bit of effort to get the USB port set up as a comm port on the laptop but it was well worth it. The onboard diagnostics are very good if you can get at them, but that takes a cable and the software. Why spend a lot of time and money shooting in the dark. Unlike some other brands that sell their diagnostic stuff for big bucks, Suzuki's is available relatively inexpensively.

Great suggestion. But I am $crewed because I am a Mac user! Looks like these are Windows only. If I had a PC, that widget would be great to have for a lot of reasons, but I can't justify buying a PC just for that!

[Rumrace]

The tear in either style fuel pump will be visible. You may find red resin clumps inside which finished it off. They die from age. Should be dirt cheap. Yamaha use a block on 4 strokes. The sealed unit used on some diesels are identical to cars except in cars there is a fuel weep hole. Gas stink alerts you the car is in limp mode. Can overheat also.