New Member, New Trojan Owner, Gas Tank Issue

[Codger]

Hey there all. I recently picked up a 1978 F-26 and stumbled across this site when searching for information about it. I've done a lot of reading on here and seems like there is great wealth of information.

First thing I did after picking up the boat was to pull out the old galvanized tank which was full of rust. I replaced it with a new Moeller 58 gallon tank, and I also replaced the water separator filter and the filter just before the carb.

Problem now is that I can't get the boat to start/run, now that i got the new tank in there. The water separator has a clear canister, and when I pour some gas in there the boat will run until it sucks it all out of the canister, but its not pulling any gas from the tank. After it sucks the seperator can dry, when I spin the canister off there is huge vacuum release, so it seems the fuel pump is working good.

I've triple checked all my connections, but am stumped at this point. Does the fuel system need to be primed since all the gas was removed during the tank replacement? Any suggestions from the experts here?

Thanks!
Rich

[k9th]

First of all welcome to the forum and congrats on your new purchase of one of the greatest boats ever made.

The first thing that came to mind was to check the anti-siphon valve to make sure it is installed correctly (not backwards) and not clogged. The second thing was to check the vent line to make sure it is clear also. The third thing is to check the pickup line to make sure it is clear and not clogged. Sometimes there is a strainer at the end that can get clogged.

If all of these are OK and the fuel pump is pulling adequate vacuum, there should be no reason it will not continue to run.

Good luck.

[prowlersfish]

I agree its most likely the one way check valve . also could be a clogged vent on the tank or pinched line/hose.

Now you said "The water separator has a clear canister" that has got to go . It is illegal and unsafe ( you insurance may not cover it too ). they can only be used on outboards and diesels can not be used on gas inboards / I/Os or gensets .

[Codger]

I'll check the check valve when I go back out to the marina.

It should be right. Its a brand new anti-siphon check valve I bought to go along with the new tank. Screwed right into the threaded withdraw fitting on the new tank and had a barbed end that I hose clamped the fuel line onto. Really wasn't possible to install backwards.

Thanks for the tip on the separator filter. I think I'll leave the clear canister on while I get this fuel pumping issue figured out so I can see if the fuel is making it up. Once that issue is solved, I'll update that to a modern filter system.

What about the level of fuel in the tank? Since after putting the new tank in, it had no gas in it and I couldn't drive the boat to the on-lake gas station, I put in approx 10 gallon from a portable tank I filled up at the local gas station. That fills the tank to about 1/6 full. I wondered if that wasn't enough to hit the withdraw hose in the tank, so I pulled the gage sender off and it looked like the strainer on the end of the withdraw tube was indeed into the gas. Maybe I need to get more gas in the tank to help it get sucked up the withdraw tube?

I'm thinking about stealing the fuel line from a small outboard motor I have (that has the manual primer bulb in the line) and attach that to the new tank to see if I can get gas to pump up out of the tank. that would answer the check valve question.

Hope to get it solved today. I was excited getting the new tank in, but pretty bummed out yesterday when I couldn't get it to run.

[Danny Bailey]

Welcome aboard. With that much vacuum on the filter bowl you have something plugged up somewhere.

[prowlersfish]

What Danny said is 100% correct . using your out board primer bulb is a great way to check for for problem . hook it up at different points you should be able to Isolate the problem area .

[plansea]

Welcome, My boat has a manual shut off valve,yours probably does too. A metal canister is a available for your filter, I think that is legal. Larry

[captainmaniac]

If you have a vacuum, you either have blockage or shutoff valve turned off. Insufficient fuel in the tank wouldn't result in a vacuum. The boat should have at least one shutoff valve in the line between tank and the engine - specs in my manual for '79 shows the shutoff between filter and engine, but perhaps some previous owner scabbed another one into the line further back.

[Codger]

Ended up being the check valve on the tank. Kinda weird since its a brand new check valve. The ball and spring inside moved readily when depressed with a screwdriver, but the force required seemed like a lot. I couldn't get the ball to move just pushing the screwdriver with my hands, I had to put the screwdriver on a table and then press with a lot of force. My guess is that the fuel pump doesn't draw enough vacuum to move the check valve.

I put a non-check valve fitting on (stolen from my outboard tank), and the boat now runs fine.

Wondering whether to just leave it with no anti-siphon, or maybe try a different anti-siphon valve (different brand or something). Couldn't really see anything wrong with the anti-siphon I bought except the force required to move the ball in there. I couldn't pump anything through it with my outboard motor gas line with primer bulb either. How strong are these supposed to be?

Overall, I'm pretty happy though. When I bought the boat, it wouldn't go over 2000 rpm because of the clogged fuel filters from the rust in the tank. Now it gets up to 4200 rpm at wide open and runs really good!

[prowlersfish]

Glad to see its fixed . would be a good idea to put a new check valve on , It should not take much to open , Its really a ant-siphon valve so if a line came off or leaked all your fuel would not drain out in to the bilge

[davidsmith]

I thought the anti-siphon valve was to keep the fuel line full from the carb to the fuel tank, Without the valve the fuel could siphon out of the carb resulting in hard starting untill the pump refills carb.

[Peter]

welcome....that is all

[prowlersfish]

I thought the anti-siphon valve was to keep the fuel line full from the carb to the fuel tank, Without the valve the fuel could siphon out of the carb resulting in hard starting untill the pump refills carb.

thats a good side effect but not the reason the C.G. requires it .

[davidsmith]

§ 183.568 Anti-siphon protection.
Each fuel line from the fuel tank to
the fuel inlet connection on the carburetor
must:
(a) Be above the level of the tank top;
or
(b) Have an anti-siphon device or an
electrically operated fuel stop valve:
(1) At the tank withdrawal fitting; or
(2) Installed so the line from the fuel
tank is above the top of the tank; or
(c) Provided that the fuel tank top is
below the level of the carburetor inlet,
be metallic fuel lines meeting the construction
requirements of § 183.538 or
‘‘USCG Type A1’’ hose, with one or two
manual shutoff valves installed as follows:
(1) Directly at the fuel tank connection
arranged to be readily accessible
for operation from outside of the compartment,
and
(2) If the length of fuel line from the
tank outlet to the engine inlet is greater
than 12 feet, a manual shutoff valve
shall be installed at the fuel inlet connection
to the engine.
[CGD 74–209, 42 FR 5950, Jan. 31, 1977, as
amended by CGD 81–092, 48 FR 55737, Dec. 15,
1983; CGD 85–098, 52 FR 19729, May 27, 1987]
§ 183.570 Fuel filters and strainers: Installation

[davidsmith]

http://www.access.gpo.gov/nara/cfr/wais ... 83_08.html