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Author Topic: Converting from electric to vacuum fuel pump  (Read 4626 times)

jagrugger

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Converting from electric to vacuum fuel pump
« on: June 20, 2011, 03:32:18 PM »

Well I think my electric pump has died so I am turning to the forum for help. The pump will run for a few seconds then stop. I can put my finger on the outlet hose and it will stop, then it will start again when I release it, then after a few seconds it will stop all together. From talking to a couple of people here it seems the consensus is it should contiously pump. Is this accurate? I have taken the electric pump off the bike and ran the fuel line straight to the carb, and have no issue with loss of power ( I posted before about losing power) so I am convinced the pump was my problem. The electric pump has been discontinued so I need to convert to the vacuum fuel pump. Has anyone had to do this? If so what parts do I need to order? I know I will need the vacuum pump, new hoses, and new intake. Do I need new front and rear intakes, or just the front intake. Am I missing anything for the conversion? During my trouble shooting it seems I have damaged the o-ring for the front intake as it leaks fuel now once it gets hot, the problem is it seems all the intakes have upgraded to the vacuum pump intakes so I am going to be forced to convert everything even if I were able to locate another electric pump.
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hx

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Re: Converting from electric to vacuum fuel pump
« Reply #1 on: June 26, 2011, 10:13:25 PM »

Hello from a newly registered GV250 owner from Germany,

I've done such conversion a few days ago due to failure of the electrical pump. I've changed both rubber intake manifolds to the modified versions and connected them with a Y-hose-connector with the vacuum-pump. I was afraid the suction of only one intake manifold was not enough for operating the pump at higher speed. The hoses were secured by hose-clips. It was a little tricky to install the carburetor and the airbox because the new parts were not as flexible as the old ones. I removed the pump-relay and hid the connector in the rubber... whatever you call it!  ;D
If the membrane in your old electric pump is ok and only the electric part is rotten: The pump comes from Mitsubishi and is used in other bikes too! I.E. Yamaha XJ 900. There exists a cheap repair-kit. You will only need to replace the electric part of the pump and thats it.

hx
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krakum1967

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Re: Converting from electric to vacuum fuel pump
« Reply #2 on: June 27, 2011, 01:24:45 AM »

Welcome aboard HX, good information
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stigger

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Re: Converting from electric to vacuum fuel pump
« Reply #3 on: June 27, 2011, 02:56:46 AM »

I don't thing you can run FI without a electric pump?
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hx

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Re: Converting from electric to vacuum fuel pump
« Reply #4 on: June 27, 2011, 04:51:34 PM »

I don't thing you can run FI without a electric pump?

Right. The FI models have the electric pump integrated in the fuel-tank and cannot run without it. Hope, that jagrugger has an older carbureted bike (I think he has an older model - because he wrote that the pump is discontinued.) B.t.w.: the FI-fuel-pump seems to bee a very expensive spare part.

hx
« Last Edit: June 27, 2011, 05:00:34 PM by hx »
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jagrugger

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Re: Converting from electric to vacuum fuel pump
« Reply #5 on: June 30, 2011, 02:26:45 PM »

Thanks for the info. So far I am still waiting on the vacuum fuel pump to get here. Does the vacuum pump mount exactly the same as the electric pump?  I had to replace the front intake anyway since the old one was leaking at the mating surface with the cylinder. Since they did away with the electric pumps all intakes are now with the vacuum connection. If need be I will order the rear intake as well, I don't get much faster than 55 mph anyway on my drive so I hope this will finally end my issues and I can get back to saving on gas money! But now I am curious about my old electric pump and wonder if it is repairable.
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stigger

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Re: Converting from electric to vacuum fuel pump
« Reply #6 on: June 30, 2011, 02:49:28 PM »

What year is your bike and is it carbed of Fuel injected???
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hx

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Re: Converting from electric to vacuum fuel pump
« Reply #7 on: June 30, 2011, 05:19:01 PM »

Thanks for the info. So far I am still waiting on the vacuum fuel pump to get here. Does the vacuum pump mount exactly the same as the electric pump?  I had to replace the front intake anyway since the old one was leaking at the mating surface with the cylinder. Since they did away with the electric pumps all intakes are now with the vacuum connection. If need be I will order the rear intake as well, I don't get much faster than 55 mph anyway on my drive so I hope this will finally end my issues and I can get back to saving on gas money! But now I am curious about my old electric pump and wonder if it is repairable.


The electric pump is originally mounted at the outer rim om the left frame. Remove the screws and leave the holes empty. Remove the pump-relay (it is located right of the old pump location and you will see two holes that will exactly fit the vacuum-pump mounting holes.) The new pump must not be installed at the old position but at the former relay-position. Don't try to use the old screws of the electric pump to mount the new one. The size of the thread is the same but the heads are to big and thightening the screws will bend the vacuum-pump and it will leak.
I'll try to add pics of my installation after this weekend.

I'm not sure about the rules of posting pics from and links to other websites here. But to prove that there is a repair kit for the pump - look at the image below or Click.

For successfull repair you only need to loosen the screw of the bottom cap of the pump, remove it and replace the old electric part with the new one. No soldering or special electrician-knowledge is required. You can solder a cable but crimping it will have the same effect. In most cases the contacts are burnt and melted or there is water in the assembly and its full of rust. To prevent the water-ingress into the pump, try to seal the "connecting line" of the pumps body with the cup with self sealing tape. To avoid burning the contacts look for a modified repair kit with "spark extinguisher". (It contains a little capacitor.) A detailed video is available at the dealers website.

All tips and instructions are for the carbureted model only. Not for the fuel-injected.

Btw: Why not only change the defective O-ring of the old intake and repair the pump if possible. This would be much less work to do and saves the bucks in your wallet...

Edit:

Intake with hose connected


Fuel pump mounted
« Last Edit: July 03, 2011, 07:37:48 PM by hx »
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jagrugger

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Re: Converting from electric to vacuum fuel pump
« Reply #8 on: June 30, 2011, 05:52:29 PM »

Thanks for the info hx it is going to help out a lot. I would have replaced the o-ring on the intake but after looking over the old one I found a couple of dry rot cracks, the factory seam was cracking as well and the aluminum piece of the intake was starting to detatch from the rubber intake so I figured I might as well replace it. I had not heard of a repair kit for the pump before you mentioning it so I just moved on to replacing the pump. I might do the repair anyway and sell it or the vacuum pump on ebay or something.
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jagrugger

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Re: Converting from electric to vacuum fuel pump
« Reply #9 on: June 30, 2011, 05:55:33 PM »

What year is your bike and is it carbed of Fuel injected???

I have a 2003 GV250, and its carbed.
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