Suzuki DF 300 losing prime at idle speed only. HELP Please!

[bcnucs]

I am leaving for the Bahamas on Thursday and I have a fuel issue I have been fighting for 2 weeks. Local Suzuki dealership is backed up for weeks and here I am. When running on a plane everything is fine come off plane and idle speed for couple minutes motors stall. Pump ball start up and go again for couple more minutes. Get on plane and it’s all good. I have spoke to Suzuki mechanics and they said pull anti siphon valves from tanks. Did that as well as all new lines and racor heads and filters all the way to the motors. Both motors doing it twin df300s. I have proper voltage of 13.5 at idle and I can watch fuel level drop in under cowling filter when low pressure pump comes on. Any suggestions would be greatly appreciated.

Ran on external 6 gallon tanks and does same thing, but refills a little quicker due to not having 10 micron filter to pull threw. Any help or thoughts would be awesome!
Here is a short video of when low pressure pump comes on, and the level in the bowl decreases drastically


https://youtu.be/B8R2k_zUg9c

[artdf175]

you must have an air leak
double check all the hose clamps on the fuel line
and check the hoses to make sure there are no holes or worn spots

[bcnucs]

you must have an air leak
double check all the hose clamps on the fuel line
and check the hoses to make sure there are no holes or worn spots

Did that. Also ran on external tank with same results

[bcnucs]

*** pretty slim on views, thought this would be the site.

[artdf175]

how do you attach the external fuel supply?
Have you checked that small inline filter for a crack
in order to drain the fuel like your video shows there is air getting in the fuel supply system someplace
there is a loose fitting or hole


the anti siphon valve on the fuel tank actually creates the opposite problem they plug the system and the fuel pump pumping fuel creates a vacuum in the system to the point of shutting down the engine
you say you put all new fuel line on
if you engines were not doing this before you replaced it, put 2 and 2 together , it's the fuel line on one of its components that is the problem
Art

Did you check that inline filter in the video for the drain plug? my 175 has a rubber cap on the bottom that you can use to drain out fuel

[Intrepid1]

it could be your IAC (idle air control) valve. that same thing happened with one of my 250's and i thought it was fuel related, but it ended up being air related.

[artdf175]

the only way air gets in the inline fuel filter, as per the video, is a bad connection in the fuel line/delivery system - no other way. That needs to be solved first
Art