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Re: Reliable on/off fuel tap for HRC setups

Posted: Tue Aug 16, 2011 1:35 pm
by Variablevalves suck
If they dribble when off and your floats dont seal correctly that fuel will go somewhere, it may go out of an over flow but could as happenes on the GSXR4's go down the bore and wash the oil off the oil rings, on start up you get premature wear and everything end in tears.
http://www.westgroup.co.uk/pdfs/Air%20L ... atalog.pdf
I going to look into one of the miniture vacuum electric switches as above, they should sense a vacuum and then switch either on or off (depends which you choose) and your pump will flow, thats how i see it.

Re: Reliable on/off fuel tap for HRC setups

Posted: Tue Aug 16, 2011 8:19 pm
by skinnydog0_0
Variablevalves suck wrote:If they dribble when off and your floats dont seal correctly that fuel will go somewhere, it may go out of an over flow but could as happenes on the GSXR4's go down the bore and wash the oil off the oil rings, on start up you get premature wear and everything end in tears.
http://www.westgroup.co.uk/pdfs/Air%20L ... atalog.pdf
I going to look into one of the miniture vacuum electric switches as above, they should sense a vacuum and then switch either on or off (depends which you choose) and your pump will flow, thats how i see it.
Chris,
If you get one up and running let me know i would be very interested. :grin:
Cheers

Re: Reliable on/off fuel tap for HRC setups

Posted: Tue Aug 16, 2011 9:58 pm
by Variablevalves suck
Jeff, will do. Ive mailed a couple of different suppliers and am waiting for a reply.
My GSXR is a simple creature and will only supply 12v from the main switch so a pump just pumps when i turn on, these vacuum electric switches will only switch the pump when the motor runs supplying the vacuum. :geek:
Just need to find one the right size.

Re: Reliable on/off fuel tap for HRC setups

Posted: Wed Aug 17, 2011 8:11 am
by lukemillar
Variablevalves suck wrote:If they dribble when off and your floats dont seal correctly that fuel will go somewhere, it may go out of an over flow but could as happenes on the GSXR4's go down the bore and wash the oil off the oil rings, on start up you get premature wear and everything end in tears.
http://www.westgroup.co.uk/pdfs/Air%20L ... atalog.pdf
I going to look into one of the miniture vacuum electric switches as above, they should sense a vacuum and then switch either on or off (depends which you choose) and your pump will flow, thats how i see it.
Been parked for 2 months and I just stripped the carbs - Nothing leaking into the heads! Besides, dribbling is more like a few drips and I've got a dry break on order to make sure!

Re: Reliable on/off fuel tap for HRC setups

Posted: Sun Sep 04, 2011 1:11 pm
by timoth123
My mrs's race nc35 has a pump that pumps when you turn the ignition on, then stops once its pressurises. thought this was odd at first. so tested it pumping into a bowl and it just keeps pumping away. handy to empty the tank.

Re: Reliable on/off fuel tap for HRC setups

Posted: Mon Sep 05, 2011 6:34 pm
by ColinP
dont no if this is any use to someone?

http://www.akhara.com/nc30/fueltapmod/index.html


;)

Re: Reliable on/off fuel tap for HRC setups

Posted: Tue Sep 06, 2011 10:01 am
by amaechizzle
I bought a 1/4" ball valve off ebay, and a couple 90 degree connecters to route it just underneath my stock fuel tap.

Double's up as an anti theft... well sorta.

Re: Reliable on/off fuel tap for HRC setups

Posted: Tue Sep 06, 2011 10:09 am
by amaechizzle
http://www.ebay.com.au/itm/160277690442 ... 1423.l2649

It's freaking tiny, and will fit anywhere. Makes taking off the tank easy, no drips whatsoever.

Great quality to.

Re: Reliable on/off fuel tap for HRC setups

Posted: Wed Sep 07, 2011 2:14 pm
by amaechizzle
Image

Re: Reliable on/off fuel tap for HRC setups

Posted: Sat Sep 10, 2011 11:49 pm
by spanky
As Timoth said, fuel pumps only run until pressure is reached. Once the bowls fill up the float valves seal and the pump stops. When I turn my ignition on the pump runs for a few seconds then gives a little pulse about every 3 seconds which I put down to having slightly leaky float valves.

One note of caution: Modern FI bikes have a tilt switch that cuts the pump if the bike is on its side. Fuel pumps on nc30s won't have this so in a crash the carb bowls will piss out through the overflow and the pump will keep on pumping.

re the tap, I have the diaphragm removed, so no vaccum needed. I also discovered a while back that a previous owner had chopped out the internal filter completly. That means ON and RESERVE both take fuel from the bottom of the tank, i.e. no reserve. The bike has an inline filter instead and I'm guessing this was a race mod where running with low levels of fuel is useful.