2016 df140 problems

[Masbama]

Motor has 35 hours. Engine was removed from boat when transom rebuilt. Found a corroded wiring harness connection. Replaced wiring harness. New fuel line from primer bulb to engine. Took for ops run. Ran great until I looked and saw tell tale stream not showing but water pressure gauge showed pressure. Stopped engine. Cleaned out stream outlet and it worked fine. Then noticed primer bulb compressed. Stopped and pumped it up but compressed again but ran fine for a while then surged especially at higher rpms. Idled back to launch. Took it to mechanic who replaced anti siphon valve. Took it out and did the same thing. Replaced primer bulb but did same thing again. Will run tomorrow on portable tank with new lines to eliminate problem with fuel system. Is it the motor? Help! Thanks! (Motor ran flawless before it was removed)

[Moonlighter]

If the primer bulb sucks flat you have a problem in your boat’s fuel system somewhere before the bulb.

So check and replace any filters in the line between the tank and the bulb.

Check the fuel lines they could have collapsed internally

Check the tank breather to see if it is blocked or the hose kinked.

If all that checks out if could be the pickup tube in the tank is blocked.

Get rid of the anti syphon valve, they are nothing but trouble.

[Masbama]

Well, it seems it is not the fuel lines. I ran it on an external tank with a new primer bulb and hose and it did the same thing. I guess I have to take it in to a dealer Will the diagnostic codes pin point the problem? There are no beeps or lights while running.

[Harper]

Well, it seems it is not the fuel lines. I ran it on an external tank with a new primer bulb and hose and it did the same thing. I guess I have to take it in to a dealer Will the diagnostic codes pin point the problem? There are no beeps or lights while running.

Might be a code that shows up, but if so, it's more likely to show a RESULT of the problem. Unlikely to show the CAUSE of the problem, since the cause is not with the motor itself.

[tommybe1]

I had a similar problem, ran a can of seafoam with 1 gal gas thru it , cleared right up, also did moonlighter suggestions, gl

[Murray]

Well, it seems it is not the fuel lines. I ran it on an external tank with a new primer bulb and hose and it did the same thing. I guess I have to take it in to a dealer Will the diagnostic codes pin point the problem? There are no beeps or lights while running.

Did you use fresh fuel? How old is the fuel in the main tank?

[Solarman]

Check direction of new primer bulb?

[noelm007]

Be a miracle if a primer bulb shows a fault code, and just as much of a miracle if you get a fault code without "beeps" a collapsing fuel bulb is not exactly complicated, a low pressure is created by the fuel pump on the engine (suction) the bulb collapsing really has nothing to do with the engine, it is a restriction between the bulb and the tank, or the bulb itself is faulty or installed the wrong way around.

[Moonlighter]

Perhaps the OP is misleading us with the comment that the primer bulb was “compressed”??

When I read compressed, I see in my mind a bulb that is sucked flat, eg where it is no longer a normal round shape and the sides are sucked in. Not just soft, but sucked in!!

As Noel said, this can only happen if the engine is sucking in fuel, but the fuel flow to the engine is blocked. Somewhere from (and including) the bulb and the tank. Or the tank vent is blocked creating a vacuum.

Otherwise, why would the bulb flatten out like that?

Same thing happens on a portable tank if the tank vent is not openned. I have even seen those ted plastic portable tanks get badly out of shape due to vent being closed while a large engine is running from them!

So if Masbama can let us know clearly about that bulb and what it is doing, then we can perhaps reconsider a course of action.

Re lack of fuel, I have seen MAP sensor fault codes happen, but you also get the beeps.

[Masbama]

The primer bulb was “sucked flat”when initial problem occurred. Then changed the anti siphon valve, bought new bulb, check vent (no issues) Tested main fuel line with new bulb and valve; same symptoms but bulb not compressed as much. Tested with external tank with new line and bulb, same issues.
https://www.amazon.com/clouddrive/sh...qGQhq9U37VB8mC

Here is is a link with existing line and new bulb. You have to have the sound up to hear the surging. The bulb does not compress like it did initially but I hope you can hear how the engine surges at a static throttle position. I have disconnected the line from the engine and pumped the bulb and gas spewed out.
I sure hope it is a fuel line issue and not the engine. The mechanic asked something about a VST part but I did not know what that is or does.
Thanks so much!

[Hoosmatroos]

If the bulb is sucked flat then the problem sits before the bulb. Vent or anti syphon valvr thr most likely cause.

In the VST there is a small filter that could be the culprit. Not too difficult to change that filter.

[artdf175]

not to get in the way of the other conversations but a question anyway
fuel bulb double check that the fuel flow is going the correct direction!
and - when in operation the directions have to the fuel bulb sitting in a vertical position with the fuel flowing out the top hole
Art

[Masbama]

Fuel flow for all three bulbs tried were pointed in correct direction. The external tank had it in a vertical position. Something happened when the engine was taken off for the transom work and put back on with a new wiring harness. Just what; I don’t know. Something in the wiring harness perhaps? I’m going to take to dealer to check it out. It’s still under warranty. Anything specific I should ask?