2014 DF175 Stalling at idle in gear

[caltexvb]

Hi,
Recently got my boat back after the 100hr service. Started at the ramp fine and motored out to a fishing spot for 20 minutes. As i reduced the throttle to idle forward it stalled. Started fine. When I shifted into idle forward it stalled again. I was able to work around the issue by starting in idle (obviously out of gear) and then quickly shifting into forward and applying a small amount of throttle. As the day went on the issue disappeared. Got back to the ramp and shifted in and out of gear 5-10 times with no issues. Got home and shifted in and out of gear while flushing the motor, still no issues.

Reading this forum and others, the IAC valve keeps being mentioned but its usually on older models with more hours.

Any suggestions appreciated.

[Moonlighter]

Might be as simple as a little air in fuel lines/filters following the service. Especially if the main water separating fuel filter in the main fuel line in the boat was changed. (You do have one of them fitted, don't you?!)

Just prime up the system with the primer bulb and see how it goes.

I would tend to just watch it, if it doesnt repeat it I wouldn't worry, if it does it again, talk to mechanic that did the service and ask them to have a look at it.

[caltexvb]

Thanks Moonlighter. Yes I did have a fuel filter change and it has a clear bulb. Yeah that's what I originally suspected but after running the engine at 4000rpm for 20-30 minutes I came to the conclusion that any air in the system would have become evident a lot sooner than that? Cheers.

[Moonlighter]

What make of boat? Your location?

[caltexvb]

Boat is a barcrusher 670c (aluminum) made in Australia. I'm also Australian made!

[Moonlighter]

Cool.

I still think air in lines likely. See how it goes next time out.

Watch the fuel filter (Racor), because occasionally the o ring gasket on the lower bowl doesnt seat right and lets air in/fuel out, could be a source of air in fuel lines. Couldnt hurt to check/retighten all the hose clamps on fuel lines either. And check that the breather isnt partially blocked by a mud wasp nest!

You've got a larger copy of my Surtees! Mines a 5.5m workmate with garaging hardtop and folding screen.

Cheers

[caltexvb]

Thanks again. Will check the fuel filter, lines, clamps etc. When you say check the breather do you mean the fuel tank breather? If not where is the breather located on the engine?

Yeah I believe Barcrusher wasn't the first to come up with the Barcrusher shape

[Moonlighter]

Fuel tank breather is what I meant. If its partly blocked it creates a vaccuum in the tank - higher revs the engine may be able to suck past it but at lower revs not enough fuel getting through so stalls....

If it does it again, have a look at the primer bulb to see if it is empty or sucked flat.

[caltexvb]

Will do. Thanks!

[caltexvb]

Btw does anybody in Australia sell service manuals for a 2014 Df175? Either PDF or hard copy?

[ChrigelKarrer]

You may pull the IAC valve and clean it with carburator cleaner.
Clean also the air passage and the seats with carburator cleaner.
If this helps, fine, if not you know that you have a clean IAC valve ...

My DF200 IAC valve died after a month, so not only at older motors.

IAC valve failure usually manifests at "cold" engine and no ideling is possible except accellerating manually, but the IAC valve controls minimum rpm tru air flow control it may be related to your problem.

Chris

[caltexvb]

Thanks Chris will inspect/clean the IAC valve. When you said yours died after a month do you mean it failed completely or worked again after being cleaned?

Like I said in my original post, the engine started fine at the ramp (cold) and the problem didn't manifest itself until reducing the power to idle after being operated at high RPM for 20 minutes. If IAC valve problems usually occur on cold engines it may not be the cause of my issue.