Fuel tank / line issues part 2

[cpoint]

Thanks, will check to see if I can find any info on tank. I did call the Florida dealer, they took message but did not get back to me. In regards to sizes, the hose says 1/2 inch. However when I replaced the 6port switch, I did get 1/2 inch nips, but they did not fit. Instead of forcing I went to store got identical size nips for the new switch which was 3/8 inches.

In regarding removal I was thinking removing and going for a test ride to see if problem is resolved, if so it is problem with anti siphon valve. in which case I would need to look for one. I did look at the attachments above link, but those are not 3/4 thread.

In regards to hose and barb, the hose says 1/2 inch, barbs were 3/8. But I will pay close attention to them. I do have 1/2 barbs to put back onto switch if needs be, but what was on their was original 3/8.

Also I am going to pull out and look at the pickup line.

[cpoint]

Source of the post What about that other fitting? Is it usable?

The other fitting? if you mean the one in middle of the tank, there is a pickup line I think. There is just a stopper on that one, no fittings. Not sure if there is a pickup line in that. I am not sure what that is. If that is same size pickup line, maybe I can use that to eliminate problem with initial pickup line. Does anyone know what that unused fitting on top of port tank on 356?

[cpoint]

OK, here is an update, not sure progress or going backwards took the anti-siphon valve from one of the aux outputs (there were 2, 1 for starboard and 1 for port. I basically switched the port tank one with aux one. The aux one was practically new, as aux has hardly been used. while at it, I removed the little housing the anti-siphon goes into. thinking that was the pickup line. luckily that came out easily, but it was just an L fitting. the tube is I think part of tank. It did not come up with the fitting. By the way I did have to cut the flooring for no reason at this point, I thought I would need it to pull it up straight. Nothing to pull up. I did look in, looked clean, so no issues. I took a clear hose I had that fit in to the tube put it all the way down. Try to plow, but couldn't. took it out measured the depth. it was 19 inches. Precisely the tank dept is 19 inches. so I was basically hitting bottom. I than pull up slightly and blew in, I hear air bubbling in the tank. So after this posting I am going to look into how that pickup look in schematics if I can find. Anyway, put everything back together tightly port and aux. took her out, started 2k rpm, all good, picked up speed slowly up to about 35k rpm. all good for few minutes. Then rpm started jumping around, dropped to 2k rpm, was fine, but then it started going up and down, mostly down. engine died couple times. once I restarted it was OK at lower rpm but after few minutes died again. At that point we went back to dock, and was hoping both engines would pull me as I have a pretty tight dock. anyway got back in all good. So conclusion 2 choices as every part has been replaced or verified. 1) bad fuel, or stuff at bottom probably getting sucked back in at bottom where pickup line I assume has little holes or 2) replace the 2 hoses. one from tank to switch and other from switch to engine. But the fact that it was good after switching the anti-siphon valve and blowing air to the bottom of the pickup line it was good briefly suggests there is matter in the bottom. so 1) is really getting fuel polishing guys a call again. Somehow hose I don't think is the issue. So should I call the fuel cleanup guys? or replace the hose try again, then call up the fuel clean up guys? any suggestions, or based on my long explanation, any ideas? anyone else had similar experience? Also does anyone know what the pickup line looks like in a 356 aftcabin?

[km1125]

If you can rig a couple gasoline-capable vacuum gauges between the fuel tank and the first pump, you'd have better info.

One located near the pump and one located nearest the tank. Fuel switches, line and filters would be between the two gauges. The gauges should only show about 1-3 mm of vacuum when you're running. If the vacuum on BOTH gauges goes up when the engine starts to struggle then it would confirm some kind of debris blocking the lift tube or anti-siphon valve. If the one at the tank stays normal but the one by the pump goes up, then you have an issue in the lines, filter or switch. If neither go up much then it would indicate you're sucking in air somewhere.

[cpoint]

OK, finally after 2 years we are back on the water
I ended up replacing the hose, not sure it was necessary, but figured replace everything between tank and engine to be on safe side. Also had had the fuel cleaning guys come out and clean the tank. They did get good deal of junk out of it, looked like black pebbles 1mm to 5mm in size. No idea what they were. Although gas looked clean at that point, still did not run, than I got 6 x 5gallon gas containers, and drained about 30 gallons that was in the port tank. Than using aux tank for port side went to gas station and picked up some new fresh gas (luckily this place no longer sells ethanol). Went out nervous as hell. went for awhile at 2kRPM. then opened it up to 32k RPM, no issues, all good Happy days are here again

[km1125]

Source of the post
.... Went out nervous as hell. went for awhile at 2kRPM. then opened it up to 32k RPM, no issues, all good ....

Where can I get some of that gas???



Just kidding. Glad you got it figured out (and came back with an update!)

[cpoint]

Source of the post

Source of the post
.... Went out nervous as hell. went for awhile at 2kRPM. then opened it up to 32k RPM, no issues, all good ....

Where can I get some of that gas???



Just kidding. Glad you got it figured out (and came back with an update!)

If you mean the cleaned up but unusable gas, sorry to say it's gone, but if I had know would have given to you

[kgarguilo]

Just went through this very close to the same thing See other thread, it is very long. I cleaned my Anti Siphon valves, and they seem to be happy. See some pics I took and a movie on one drive link below:

https://1drv.ms/f/s!AsUXzq27eR2fgsAwFD8 ... w?e=HBtthb

Also, my boat is a 406 and the Anti Siphon valves (CS 1/2“ Brass Check Valve Viton Seal) new can be purchased here for $57.00 each

Circle Valve Technologies, Inc.
1533 Gehman Road | Harleysville, PA 19438
p: 267-933-6300 | e: sales@circlevalve.com

Good luck!

[cpoint]

Thanks for the info and pictures.