Fuel Pickup Operation

[rayrick]

Hi all,
I just picked up my first pair of PWCs. One is a 96 GTX. I'm taking all the advice I've read and replacing all the gray fuel lines and putting rebuild kits in the carbs. I also am going to pull the fuel pickup and check for debris in the tank and replace the fuel strainer.

I replaced the selector switch and the filter under the steering is clean.

I want to be sure I understand how the fuel pickup works. Am I correct that there is nothing mechanical in the pickup that actually pumps fuel? It's truly a pickup, yes? Meaning that it sucks up fuel by the fuel system creating a vacuum basically?

There are two pickup hoses, one stops about 2 inches or so before the other so that the final portion of fuel is reserve. Do I have that all right?

When I pull it, other than the strainer and checking for yucky stuff in the tank, what other things should I be looking for?

 

[mikidymac]

That’s all correct. The only thing left to check is the resistance on the fuel gauge sending unit. And make sure the float actually floats in fuel.

 

[GGuillot]

what other things should I be looking for?

Doesn't hurt to make sure the positive and negative vent pressure check valves are good. When I went through the fuel system, I took them off the ski and sprayed brake cleaner in them and blew them out with compressed air. Don't get them mixed up, different relief pressures for the tank. Lower one below the rail allows excessive pressure out and the other one up high above the rail relives vacuum pressure. They're both essential for proper operation of the fuel system.

 

[rayrick]

Doesn't hurt to make sure the positive and negative vent pressure check valves are good. When I went through the fuel system, I took them off the ski and sprayed brake cleaner in them and blew them out with compressed air. Don't get them mixed up, different relief pressures for the tank. Lower one below the rail allows excessive pressure out and the other one up high above the rail relives vacuum pressure. They're both essential for proper operation of the fuel system.

Ok, where are these? There is a check valve that is in the hull to the right of the handlebars and a pressure relief valve that exits the hull on the front right side. Those are the only two listed in the fuel diagram. That check valve is functioning. Is there another one?

 

[GGuillot]

Those are the only two listed in the fuel diagram. That check valve is functioning. Is there another one?

Nope, just those two..

 

[rayrick]

Nope, just those two..

I installed the valves the same way they were there, and they were attached to gray fuel lines so I'm guessing they have not been messed with. However, I'm going to double check them to be sure they are in correctly. The check valve (the one near the steering) should let air IN to the tank, yes? The relief valve on the side under the bump rail should let pressure OUT. Is that correct?

 

[GGuillot]

The check valve (the one near the steering) should let air IN to the tank, yes? The relief valve on the side under the bump rail should let pressure OUT. Is that correct?

Yes, that's correct, but they each relieve at different pressures, don't get them mixed up, weird shit can happen. Ask me how I know? On my first trip out with the GSX the tank collapsed on itself, it caved in, fortunately, when I got home and pulled the front bin I caught it. Loosening the gas cap the tank sucked in a bunch of air and eventually went back to the original shape.

 

[Ckrawiec]

Yes, that's correct, but they each relieve at different pressures, don't get them mixed up, weird shit can happen. Ask me how I know? On my first trip out with the GSX the tank collapsed on itself, it caved in, fortunately, when I got home and pulled the front bin I caught it. Loosening the gas cap the tank sucked in a bunch of air and eventually went back to the original shape.

Vacuum is an amazing thing...you wouldn't think a fuel tank (fairly rigid plastic) would collapse...but ever see them implode 55 gallon drums...yeah I know thin steel but its steel nonetheless.....funny stuff.