Electric Fuel Pump GS1100

[Guest]

Hey everyone, some of you may have seen my post over in the Racing forum about the Bonneville bike I am building. One of the requirements to race there is that my bike needs to have "positive fuel shutoff" that can be operated "without the riders hands leaving the handlebars".

I am thinking that since I will be moving the fuel tank to below the carburetors anyhow, maybe I should find a low pressure, low output inline pump to handle fuel delivery (the positive fuel shutoff happens when the pump is turned off). Does anyone have any experience with using an electric fuel pump on these bikes? How much pressure would be too much for the floats?

If anyone has any other ideas that should conform with the rulebook, I am all ears!!

Thanks!
-Len

[Sandy]

What comes to mind is the original FZ series (750/1000) Yamaha's of the mid '80s. They were carbureted, had fuel below the carbs and electric fuel pumps. Perhaps finding a tank from one of those and using the components could be a start? Here some on ebay ...cheap like borscht. If capacity is limited for your application just use two.

https://www.ebay.com/b/Motorcycle-Fuel-Pumps-for-Yamaha-FZR1000/177780/bn_20522328

[GregT]

Most (if not all)of the out-of-tank fuel pumps have built in pressure regulators which will cut off supply at the correct pressure. For carbs which were designed for gravity feed, the pressure is actually pretty low - around 1.2 psi. Yes one point two psi. I used to set up a lot of carbs on small speedway cars which were pump fed so had to have the right gauges...
In your application, I'd look at the bigger Hondas which had pump feed and maybe the V-Max too. You need plenty of volume.

The positive cut off can be as you suggest, a separate power feed and switch for the pump - or there are solenoid operated valves available which would be used in a gravity fed application

[stevef.]

Thanks for the insight!!

Follow-up question: All of the fuel pumps mentioned here show pressure of 2-4psi. Will that be ok? Greg mentioned a maximum of 1.2psi for gravity fed carbs. Also, if it makes any difference, (I'm sure you already know) the petcock is vacuum operated, would carbs fed from a vacuum petcock handle 2-4psi without over-filling the bowls?

-Len

[850 Combat]

I would consider a 12 volt solenoid valve lsimilar to this:

https://www.amazon.com/dp/B01M7PFYTX/ref=asc_df_B01M7PFYTX5211323/?tag=hyprod-20&creative=395033&creativeASIN=B01M7PFYTX&linkCode=df0&hvadid=198075593684&hvpos=1o5&hvnetw=g&hvrand=1688531959123954851&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031579&hvtargid=pla-350240270334

You could wire it through the kill switch, and use a relay if necessary. I would consider a valve a positive shut off more than I would a pump, with a system that can use gravity for fuel flow. You can buy 1/4" mnpt x whatever fuel line you want to run.

[stevef.]

I would consider a 12 volt solenoid valve lsimilar to this:

https://www.amazon.com/dp/B01M7PFYTX/ref=asc_df_B01M7PFYTX5211323/?tag=hyprod-20&creative=395033&creativeASIN=B01M7PFYTX&linkCode=df0&hvadid=198075593684&hvpos=1o5&hvnetw=g&hvrand=1688531959123954851&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031579&hvtargid=pla-350240270334

You could wire it through the kill switch, and use a relay if necessary. I would consider a valve a positive shut off more than I would a pump, with a system that can use gravity for fuel flow. You can buy 1/4" mnpt x whatever fuel line you want to run.

Sweeeeeeeeeeeet . I don't know why but I have been unable to find these up until now! This is very helpful, Thanks!!

Although, if we end up deciding to relocate the tank from above the engine, we will have to use a fuel pump anyway.

And just as an FYI, I have seen that turning a fuel pump off is actually considered a positive fuel shutoff. All modern bikes with pumps get away without having one of these on the salt.

[GregT]

Sweeeeeeeeeeeet . I don't know why but I have been unable to find these up until now! This is very helpful, Thanks!!

Although, if we end up deciding to relocate the tank from above the engine, we will have to use a fuel pump anyway.

And just as an FYI, I have seen that turning a fuel pump off is actually considered a positive fuel shutoff. All modern bikes with pumps get away without having one of these on the salt.

If you do relocate the tank - presumably for a lower riding position ? - use a bike specific pump. Car carbs are made with float valves and floats sized for around 4lb pressure. In my experience 4lb on bike carbs will simply put a large amount of fuel down the bowl overflows.
Re cutoff to the pump. Couple of years ago I set up a '92 750 aircooled Ducati for our street racing - for which we have to have a "deadman" pull - out switch attatched to the rider which is supposed to cut everything off...I was most surprised to wire it in to the kill switch on the bars and then find that the pump still ran. Some major surgery on the main harness was required to get it to actually kill everything.
At major street races here we'll often see a scrutineer pull the switch on a bike running in the pits or dummy grid. Surprising how often auxiliaries like the pump still run...

[hillsy]

This will do it:

http://www.ebay.com.au/itm/12v-80-LPH-Fuel-Pump-For-Honda-CBR600F-CBR600F2-CBR600F3-TRX350-TRX350D-/281705902650?hash=item4196faf23a:g:lAEAAOSwv0tVaBil

[850 Combat]

I've had good luck with Facet cube type electric fuel pumps on cars with weber carbs and Delortto carbs without using a fuel regulator. I did try a Holley fuel regulator, but I deleted it with no ill effects when trying to fix an intermittent electrical problem by working on the fuel system.

http://www.facet-purolator.com/cube-fuel-pumps.php