Fuel pump not pumping. By turboblue (Read 11,947 times)

[turboblue]

I have a 150cc. I'm just not sure if I have the lines hooked back up right. This is my problem. If I reverse the lines then I see gas in the vacuume line. If I put it up the way it is now it doesn't suck gas out of the tank. I cleaned out the gas tank with vinegar and that really came out great. I also cleaned out the carb because it was stalling out again. Not getting fuel. If I put gas straight to the carb it runs great until its out of the line.
In the pictures I have the fuel line going in the bottom of the pump. I have the fuel line going to the carb on the port outside the pump. And the vacuume line is on the port that's is on the inside of the pump. I hope I did not get you guys confused..

[turboblue]

s1069.photobucket.com/user/wendymorris92/slideshow/

[mikey34]

Does it have a Vacuum Petcock? If so, pull really hard on the vac side, and make sure it is opening up fully. I don't have any experience with those Vac pumps, my 50 is gravity fed. Good Luck!

[turboblue]

It has a fuel pump with vacuum just doesn't seem to pump. It worked for awhile then it stopped. Thought it got plugged up with the gunk in the tank. Thanks for trying to help.

[Alleyoop]

Take the VACUUM LINE going to the FUEL PUMP and Take the FUEL LINE OFF THE CARB stick it in a container. Just in case the Fuel Pump is allowing gas to come out of the Vacuum line use a Turkey Baster or something to apply suction I don't want you to be swallowing fuel. When suction is applied fuel should come out into the container and stop when no suction.

Now is the VACUUM LINE HOOKED UP a CONNECTOR on the INTAKE MANIFOLD like this picture:
Alleyoop

[turboblue]

Just don't get this thing. I pulled the gas line off and put a suction on the line and gas came through the line. I reconnect it and still no gas. I do have bigger lines on the gas tank and pump. But on the carb has smaller lines. So my bright idea was to put the smaller lines inside the larger lines then I put zip line on them so they are air tight. Still it don't pull the gas through the line. I did notice when I had the bigger lines on the vacuum line I would feel pulsing but not enough to pull it up. I do see the gas trying to move up the line to the pump but doesn't get it to the pump. Any ideas? Thanks for all your help!

[Alleyoop]

Where is your FUEL TANK Behind the SEAT HIGHER than the CARB. Or is your fuel tank LOWER THAN the CARB?


1. the fuel line from the CARB to your FUEL FILTER SHOULD BE 3/16 ID(SMALL HOSE)
2. The FUEL LINE from the other side of the FUEL FILTER should be 1/4ID(bigger hose) going to the PUMP( either PETCOCK or FUEL PUMP) TWO different pump depending on where you gas tank is(QUESTION ABOVE THAT I ASKED)

3. IF tank is above the CARB you have a PETCOCK, that is a GRAVITY FED FUEL SYSTEM.
a. The fuel line and PETCOCK and FUEL FILTER MUST not have any UPS OR DOWNS or in any WAY BE BELOW the CARBS FUEL INLET NIPPLE.

On a GRAVITY fed system you want the STRAIGHTEST shot to the CARB GOING DOWNHILL(VERY IMPORTANT) otherwise the fuel will have a hard time getting to the carb and filling the fuel bowl.
Alleyoop

[Bashan]

I wasn't sure if you still needed line IDs or not. Just in case, here they are using your pic:

[Alleyoop]

The fuel from the TANK is BEFORE the pump not good. Looks like the fuel line goes up and down and should be a straight shot to the carb.
Alleyoop

[turboblue]

I do not have a gravity feed system. My tank is under the handle bars by my feet. In the pictures are you telling me that I need to put the fuel line from the tank on the other side of the pump. Where you have labeled it fuel out? The pump is pretty even with the carb. There isn't any kinks on the hoses either. Thanks for labeling my pictures.

[Alleyoop]

Ok you then DO have a fuel pump,
But let me ask this the pump where is it mounted. Is it mounted on the bottom of the frame or on the side of the frame and high.
Here is my FUEL PUMP it is mounted about 18 inchs from the tank on the bottom of the frame so the gas from the tank actually runs down to the pump then the pump will have plenty of gas all the time to pump it to the carb. I think that is what is causing your problem. The pump is high and the gas from the tank cannot reach the pump which is high.
So MOUNT the pump on the bottom of the frame and gas will always flow to the pump, the pump will then pump it up to the carb, no problem.
Alleyoop

[Alleyoop]

And here you can see my FUEL FILTER GOING UP to the carb about a foot away. The Fuel Filter is about 2 1/2 feet away from the pump which is on the bottom frame up close to the tank in front.
Alleyoop

[turboblue]

Ok Ill give that a try. The pump is high on the frame above the gas tank. Ill see if I can move it down 6 inches. The pump is in the original spot on the bike. I just cant believe that they would put it in a bad place. But I do like the idea of moving it. Thought about it, but its in a bad spot to take it off. Ill have to remove all the outside panels just to get to 2 little bolts off. Thanks a bunch!

[turboblue]

Thanks Alleyoop! Totally worked! I lowered it a bit and put zip lines to hold it to the frame. Gas is shooting in really good. I'll have to give it a test run this weekend if its not raining. Thanks so much for all your help!

[Alleyoop]

FANTASTIC!! Yea I just happened to see the gas in the line not reaching the pump because the gas had to go up to the pump by gravity and that will not work.
Good news
Ride Safe
Alleyoop