No Prime - Puzzled

[Jason2tpa]

As part of my helm rebuild, the fuel/water separator and primer bulb were moved from under the center console to the transom. The fuel tank outlet hose (direct from tank) was not modified or moved or anything likewise. I hooked up this fuel outlet hose to new fuel/water separator and primer bulb and cannot get prime. I removed the fuel/water separator from the equation...still no prime. I moved the primer bulb from the transom area back to its original position nearest the tank....still no prime.

So we've got a full fuel tank, a 90º elbow, 5 feet of fuel outlet hose, and a primer bulb. Prior to this rebuild there were no fuel issues. I even removed the primer bulb and hooked up a hand siphon pump in is place to apply greater vacuum pressure in hopes to pull the fuel out....nothing but a mist or drizzle. I'm completely puzzled. Everything points to there being a hole in the hose between the fuel tank elbow and the primer/pump.....but I haven't touched this fuel hose during the rebuild. And given all my attempts to prime today, if there were a hole in the outlet hose then I would have fuel leakage in the bilge (fuel coffin has drainage holes).

The fuel access hatch is down and new console and rigging hooked up to helm.....Think I'm gonna need to detach all the rigging and the helm to open the access hatch so I can get at the fuel outlet hose. Gosh I hope not, but I'm out of ideas. Any suggestions? What are your thoughts about opening fuel fill cap and applying positive pressure to the fuel outlet hose instead of vacuum?

[oldmako69]

How old are all the bits?

It might be time. Bad stuff happens to fuel hose. Especially if you're burning Ethanol. I'd start with new hose, tank to bulb, bulb to separator, separator to engine. Toss in new clamps while you're at it unless you're convinced that they're in great shape.

Ensure that the mating surface of your fuel separator is pristine. They have a tendency to corrode and when you unscrew the old one, you compromise the mating surface. Make sure it's smooth.

Fill the separator to the brim with fuel. Then screw it on, tight.

Double-check the arrow on the squeeze bulb. Sorry.

And, consider these....
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I have tried numerous squeeze bulbs over the years. Most SUCK. Or, rather they barely suck. These move gas.

OB fuel pumps tend to be flimsy and will not tolerate much in the way of fuel delivery compromise.



Good luck.

[Jason2tpa]

All fuel components between the tank and engine are new except the fuel pick up line, which worked w/o issue when connected 3 weeks ago to the old components. Primer bulb arrow definitely orientated correctly (thanks for asking). I just find it hard to believe the fuel pickup line spontaneously failed during the 3 weeks my rig has been idle during the rebuild. But hey, stranger things have happened.

Thanks for the feedback!

[oldmako69]

I chased fuel delivery issues with my last boat. I learned to question everything. Perhaps not much else, unfortunately. It would not, under ANY circumstances pull fuel to the separators. They had to be filled to the brim.

[panasonic]

Jason

Do you have a compressor? If so try blowing air back into the fuel tank. Perhaps there is something blocking the fuel pick up...a rag or some other thing that shouldn't be in the tank. Make sure tank vent is clear before you try it.

[pstephens46]

How old are all the bits?

It might be time. Bad stuff happens to fuel hose. Especially if you're burning Ethanol. I'd start with new hose, tank to bulb, bulb to separator, separator to engine. Toss in new clamps while you're at it unless you're convinced that they're in great shape.

Ensure that the mating surface of your fuel separator is pristine. They have a tendency to corrode and when you unscrew the old one, you compromise the mating surface. Make sure it's smooth.

Fill the separator to the brim with fuel. Then screw it on, tight.

Double-check the arrow on the squeeze bulb. Sorry.

And, consider these....
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I have tried numerous squeeze bulbs over the years. Most SUCK. Or, rather they barely suck. These move gas.

OB fuel pumps tend to be flimsy and will not tolerate much in the way of fuel delivery compromise.



Good luck.

I always fill the new separator with fuel prior to twisting it on bracket. Some do not and don’t seem to have issues. But, now that I read your post again, you can’t get fuel up the line prior to attaching fuel line to bracket? Loving the new stainless bracket I bought a couple of years ago. No more AL fur.

[oldmako69]

Where did you find the stainless brackets? Racor or Yam?

[99yam40]

there should be an anti syphon valve leaving the tank.
and there could have been a bug that plugged up the opening leaving the tank if you left it open when doing all of that work for 3 weeks.
but then if it was plugged up there would be a vacuum formed and the bulb would collapse and not expand back out when pumping it

I also agree with you that putting some air pressure on the line with the gas cap off to keep from pressurizing the tank, might lead you to finding a leak using soap bubbles at all joints

[pstephens46]

Where did you find the stainless brackets? Racor or Yam?

Marpac brand
Yamaha filter, link below. Rodbolt suggested using the Loctite 518 anaerobic gasket maker instead of the plumber tape on the threads. Worked great. Permatex makes one too.

https://www.ebay.com/itm/Marpac-Univ...75.c101224.m-1

[oldmako69]

Wish I had seen this. Replaced both of mine the first week I bought the boat. They were corroded to hell and back. Cannot believe the PO was running offshore with them, and can't believe they still held a vacuum.

I covered them with Fluid Film, so they ought to be good for several years of neglect. They're in the bilge. UGH.

[Jason2tpa]

Problem solved....the inner tube delaminated then shriveled causing an obstruction



IMG_1263.jpg

[oldmako69]

Congrats. What is the location of that tube, and do you burn E10?

[99yam40]

was it plugged up or sucking air from that?

[oldmako69]

I'll post this for the next guy chasing phantom fuel issues because it's similar in that it's a fuel obstruction.

2004 F225s with less than 400 hours. ALL of it E10.

The fuel was dissolving the inner bore of the fuel lines on the engine. The high-pressure fuel pump in the VST delivers more fuel than the injectors can handle at all RPMs. The injectors are in an open loop. What fuel is not burned is returned to the VST. If the fuel lines in that loop are compromised, anything that is sloughed off is dumped into the VST. The tiny screen on the bottom of the high-pressure pump will clog with tiny flakes of rubber. Your engine will not produce full RPMs due to fuel exhaustion.

You get to pop the VST and clean the screen.

In my case, I needed to change out those fuel lines in the loop. With 400 hours they looked pristine externally but were puking black rubber crap into the VST. Pull a few of them and run a pipe cleaner through them. See what you get.

Don't think that because they look new that they're not the culprit if you're burning ethanol.

[Jason2tpa]

Below deck fuel tank...pickup line surfaces above deck about 3 feet from connection w/tank then trails aft to engine under the starboard access hatch. Plugged up flow.