DT140 not running, getting spark n fuel

[artdf175]

I am getting into your conversation late but I don't see any reference to fuel source
Almost sounds like there could be water in the fuel
How old is the fuel you are trying?
There is nothing in the pre fuel pump filter?
Should double check low pressure fuel pump to make sure it is working
Take the fuel line to high pressure off put a short hose on the "out" side and into a container and turn the motor over
Is should be preally pumping and with clear fuel
If okay then go to the high pressure pump an drain old fuel and start over there
From your conversation it really appears to be a fuel related issue
You would not get it to run 5 or 10 seconds even, if it was a wiring issue
Art

[qzone83]

You know, I never really considered water in the fuel. It isn't that old, maybe a month before the swap. But I suppose it is possible. The other motor is fine and the fuel is the same age. But they are completely sep systems. I'm going to get a few gallons of fresh clean gas tonight and give it a shot tomorrow, that should provide the answer. To that question at least. Honestly it is probably the most obvious answer, just never considered it because I knew the gas wasn't that old.

[artdf175]

You might have been able to swap sources with the 2nd engine???
However don't forget to drain out the old fuel for any fuel bowls etc
I have a friend with a lake boat that somehow got water on the fuel tank
He took the motor in and supposedly after they discovered the water problem and he got a new tank and hoses - it still, at first, would only fire on starter fluid
I gradually got it to run short bursts and finally got it running kind of hit and miss then after 10 minutes or so it would run ok stop/start
It was a matter of getting the last drop of water out of it
Good luck

[qzone83]

Well it's not good yet, but it is way better than it was. Got a 6 gallon gas can of fresh gas without oil in it. Fired right up and ran for about 15 minutes on the hose at the house. Put it in the water and fired right up again. Revs a little, but then cuts out. Went through this for about an hour. It seemed to get better, then worse, then better. It would rev up like its supposed to with throttle, then die out and shut off. Then start right back up and do the same thing with throttle. Guess I'll try to flush it again with some clean gas and swap out some plugs that have never been fouled. The other motor runs like a sewing machine. Was quite surprised at how quiet they are in the water, not like pissed off chainsaws like the 70 yamahas that came off the boat.

Thanks for all of the help and advice.

[artdf175]

That's good progess
Did you drain the fuel rail and high pressure fuel reservoir ?
Any place that old fuel could be trapped in
Art

[qzone83]

reservoir yes, rail no. going to get some new plugs in a little bit so I can start fresh. then I will drain everything before I even think about running it. hopefully that fixes it. if it does, then I have a lot of siphoning to do. About 30 gallons of premix in the tank.

[artdf175]

Have you tried pumping out a gallon into a container and seeing what comes out?
Also change out the water/fuel separater filter and see what you get out of it

[qzone83]

Well I tried that and it has been sitting for a week, still no separation. However, it is nice and blue because of the premix. This turned out to be the culprit. It didn't bother the other motor, but the premix was what was behind the whole problem. Hooked up to straight clean gas, changed the plugs, and she runs like a top.

Unfortunately, I ran into another issue with the thermostat housing. It had a slight drip so I figured I would take off the cover and re-seal it. Well that turned into 4 broken bolts, 2 broken drill bits and a broken easy out. Final solution to this problem. Drill the whole thing out and re-tap the hole. I'll get on the water one of these days.

[artdf175]

that's a good report... pleased you were able to keep working at it until you find the right key to solving the problem
we can only give you some ideas that might help but you have to do the work

sorry for the bolts ... it seems to be a problem here and there... the stainless bolts are softer than regular steel bolts and a bit of corrision sometimes is all it takes foul up the removal process
goes for putting them back in as well... when I was checking valve clearances, trying to get the right torque on one, the head just twisted off.. fortunately that was an easy fix..

Art...

[qzone83]

Well I thought the problem was fixed, but after sitting for a week, post thermostat housing fix, the gremlin is still there. Now I'm back to having no spark. Nothing has been touched, other than the thermostat housing. I touched nothing to do with the spark, but spark is gone. or at least really weak, cuz it ain't firing. Guess I'll keep trying to trace this stinkin gremlin.

[Solarman]

OK, so maybe the kill switch (you did say it started in gear and ran) could be loose/ going bad? Likewise, you may have a problem with the gear count coil, or timing coil sensor, relating to output from magneto? The premix fuel should not be a problem, if it isn't too old.
Check the wires going under the flywheel.
Do you have a manual? Check the readings on the electrical components. Gear counting coil, low and high charging coils, tps valve, oil and temp sensors.
You have already checked fuel pressure at top of the fuel rail.

Good luck, post back what you find out.

[qzone83]

Ok, final answer on the fix....the little sensor next to the flywheel that counts the teeth to tell it to spark. Replaced this relatively inexpensive piece and viola, runs perfect. Had it out a couple times now and runs as it should. Thanks for all of the advise

[Solarman]

Glad to hear it is running. Happy new year. Happy boating.