WTB 87 vfr fuel pump

so the lil plug that goes into the pump. I used the multi meter to test it. stuck red in one side and black in the other I get nothing. if I take black and leave red and put black on battery negative I get .5v

 

Can a mod close this thread

 

Gravity feed works just fine. What makes you think it will not?

 

i read that it doesnt work on the bigger motors? how would i set this up? if possible? so i dont need a new pump

 

Not at all, I have run gravity feed on everything from 500's to 1000's with no issues at all. Typically when you read "It doesn't work" comments it is because the owner is trying to fix an unrelated problem by getting rid of the pump. Since the pump wasn't the root cause of the problem it is also not the solution. In your case, if everything else on your bike is working properly it will run just fine without the pump. If not you have something else going on.

 

How would I go about setting up gravity feed?

 

It's pretty straightforward: just run a line directly from the output of the tank to the input at the carbs. Make sure to use a short length without any kinks or tight bends. Also, do not run a filter in line. Paper filter elements are too restrictive and gravity cannot push through them. In case you are concerned about this, Honda made every carburated motorcycle after the late 80's with gravity feed and none of them had a filter. If you think there might be some rust scale in your tank you can put a sintered bronze filter in line. Those will catch the big pieces while still offering full flow. These are the small ones that dirtbike guys use and are available at any dealership for $5.

Good luck!

 

I tried the gravity feed on my 700... while it worked I wasn't able to use the bottom half of the gas tank.....YMMV.. I used a Mr.Gasket 2PSI fuel pump works like a champ Haven't had a lick of trouble

 

I've heard of this before, yet I've never experienced that with any of my bikes. Low pressure pumps do not pull the fuel from the tank - they also rely on gravity feed to get the fuel from the tank to the pump. If the tank can be drained fully with a stock pump it can also be drained fully with gravity feed. Once again, the caveat being that everything else is in working correctly.

 

I cut the line to shorten it and tried to gravity drain on a 3/4 of a tank of gas and it didnt work.

 

I am in agreement with Jaime on this one.

Did you make sure there was no air lock in the fuel line ?
When I tried gravity feed it didn't work but once air was remove it ran fine.

Also you need to make sure your vent hole on the fuel cap is clear.

 

Something else is wrong then. The stock fuel pump doesn't have much of a "draw", so it relies on gravity feed to get the fuel to it. I'd look at your vent in the cap first.

 

Jamie's advice worked for my '84 VF500F beautifully -- but it got even better after the fuel valve mod here: Daugherty Motorsports - Tank Valve Petcock Modification