Landracing Forum

East Coast Timing Association => ECTA General Chat => Topic started by: gsxr1000dave on October 25, 2014, 02:51:19 PM

Title: fuel valve for motorcycles???
Post by: gsxr1000dave on October 25, 2014, 02:51:19 PM
I read in the rules that they require you to have a fuel valve to kill the fuel supply. Most old carbureted bikes have fuel shut off valve but none of the newer fuel injected bikes do. Is this something that they will fail you for??? Thanks
Title: Re: fuel valve for motorcycles???
Post by: Seldom Seen Slim on October 25, 2014, 06:17:48 PM
If your bike is old enough that the fuel pump is located outside the tank and/or non-electric -- you'll need a shut off valve that's mounted on the handlebars and actuated without having your hands come off the bars.  Usually it's a Pingel or something that has a bellcrank-type lever attached to a cable that goes to the valve and is actuated by the rider's thumb.  This goes for both fuel classes (Gas and Fuel).

If your pump is electric and does shut off when you throw the master kill switch (these days usually mounted for right thumb actuation) then you need nothing further for gas class.  For fuel class I think (not positive, though) that you'll still need the cable or something-actuated lever switch for your thumb to move.  If you're running nitrous cutting off power to the solenoid is enough.  If using nitrous, though, make sure to have an easy to find, easy to read label so the safety workers can find the shutoff valve immediately upon reaching the bike after an "incident".  The inspectors will gladly tell you if the shutoff valve isn't easy enough to find.
Title: Re: fuel valve for motorcycles???
Post by: MiltonP on October 31, 2014, 11:46:50 AM
Your tether kill switch, in addition to the thumb operated kill switch, needs to kill the fuel pump.  Most wire them in to that circuit anyways so you should be good to go.  Like Jon said, you will also need to kill the solenoid if running nitrous.  See you in the Spring.
Title: Re: fuel valve for motorcycles???
Post by: revolutionary on October 31, 2014, 12:30:52 PM
If I have a nitrous momentary switch on the handle bars and an additional in line on/off switch near the solenoid, is having the momentary switch by my thumb not enough? It removes power to the solenoid when I am not pressing on the button.
Title: Re: fuel valve for motorcycles???
Post by: MiltonP on October 31, 2014, 03:26:53 PM
I would go with what some of our nitrous running inspectors have to say as far as pass fail.   We have passed systems that have some other part of the circuit that must also have conditions met such as a 100% throttle requirement.  If you only have a momentary switch then my concern for you would be what can you do as the rider if that push button sticks or shorts somehow in the on position. 
Title: Re: fuel valve for motorcycles???
Post by: RansomT on October 31, 2014, 03:27:34 PM
If I have a nitrous momentary switch on the handle bars and an additional in line on/off switch near the solenoid, is having the momentary switch by my thumb not enough? It removes power to the solenoid when I am not pressing on the button.

In other words, if you are separated from the bike there isn't anyway the solenoid will activate?  Like MiltonP said, does it also have a WOT switched involved?
Title: Re: fuel valve for motorcycles???
Post by: revolutionary on November 13, 2014, 04:12:07 PM
If I am separated from the bike, my tether will remove power from the ignition and solenoid.
Title: Re: fuel valve for motorcycles???
Post by: Leigh Griffiths on July 07, 2017, 04:58:58 AM
I got a huge backfire and the bike runs until it starts to smoke. Could the backfire have blown the vacuum part of the vacuum valve?
Title: Re: fuel valve for motorcycles???
Post by: joea on July 07, 2017, 11:05:50 AM
What does it do when you take the existing fuel tank off ..and start it with a temporary alternative fuel supply ?
Title: Re: fuel valve for motorcycles???
Post by: Stainless1 on July 07, 2017, 11:21:02 AM
Check compression!
Most bikes with a vacuum operated gas valve have a prime selection that bypasses the vacuum.  But we digress, I don't think those valves are legal as a shutoff.