View Full Version : Hayabusa tip over sensor and some fueling questions too!

02-07-2008, 07:45 PM
I've heard a couple different stories on this but I need to know for certain. *The application is an ATV powered by busa engine. *I've built a couple of them but I have always utilized the factory sensor and just glued the "ring" in the center of the pendulum so it would give the correct reading. *I do not want to use the sensor at all and bypass it completely. *Per the manual and Busasandrail (thanks!) the resistance should be 60-64 ohm across that sensor. *I currently have it wired up to be within that resistance, but I do not believe it is correctly bypassing it. *Reason being is I'm still not getting my fuel pump to trip when the key is "on" and the kill switch is flipped to "off." *So, is it possible (and how so) to bypass that tip sensor?

Next question that is probably directly related to above is regarding the fuel pump wiring. *The engine is a 2004 and I am running an RCC stage 1 on it with an aftermarket, external fuel pump and regulator. *The instructions say to just splice into the factory fuel pump power wire on the 4-wire brown connector (I believe is is Y/R or Y/O) for the power line to the new fuel pump and keep the factory brown harness connected. *So essentially you gut the factory fuel pump and remove the regulator but keep the factory harness plugged in. *I am not using the factory fuel pump housing at all and was wondering what to do with the 3 additional wires from that brown harness. *I am not using a fuel gauge in my custom tank but I feel that I am missing something important by not having them connected. *Could that be related to my problem described above?

I have ALL other sensors appropriately bypassed and I know they are correct. *With the ignition on, in neutral, and kill switch off, the fuel pump does not pressurize or even turn on, but the engine will turn over when I hit the starter button. *I haven't checked for spark but I doubt it is there with the symptoms I am seeing.

Thank you all for your input!

02-07-2008, 08:31 PM
If someone here does not know the answer I would call and/or e-mail Scott Horner at Heads-Up Performance and ask him. You could also pose the question at Hayabusa.org. A call to RCC might be first . . . .

02-07-2008, 08:32 PM
When the kill switch is off, the fuel pump is not supposed to run. It cuts fuel incase the engine wants to diesel or a line breaks. The yellow red wire is your positive hot wire, the black/white is your ground, and the other two are for your fuel light, so just cap them off. My fuel pump on my 750 doesn't run with the kill switch off. Only on. Is the gas light on the dash illuminated? If so, some bikes have a safety mode, but that is rare.

02-07-2008, 10:47 PM
Also double check the resister you installed, it needs to be 60-64 K ohms not 60-64 ohms. Thats probably*one of the problems....and plkracer is right about the wire color for the fuel pump.

02-08-2008, 12:09 PM
Thanks guys. *I should clarify as my words seem to be slightly ambiguous regarding the kill switch position. *When attempting to get the fuel pump to trip, the kill switch was in the "run" position, not the "kill" position so there is no reason why that should be the culprit. *I do apologize for my wording though.

plkracer - I am not running the dash so I cannot verify that fuel light.

Great call Jerry on the "K" regarding the resistance. *I'm only off a few thousand there so that is probably the issue. *[smilie=banghead.gif]

Thank you for your help and I'll try and get a much larger resistor to put inline.

02-08-2008, 08:00 PM
Well sure enough, I was off by a factor of "K" in my resistance. *Picked up some larger resistors, wired them in, and she popped right off! *Thanks again for your help and I'll post some pictures soon.

02-08-2008, 08:02 PM
Cool! Hope it runs good!