WTH!!!! 50 mile trip = 1/2 a tank of gas

[CrazyMedic]

So I took the bike to school for the first time today 50 miles round trip. I never really got on it (well maybe a few times ) but nothing really major. Most shifts were between 4 - 5k. When I got there, I was already at 3/4 a tank. When I got home I was at 1/2. Somethings screwy here. Dont know what. Any ideas? Plans are to swap my exhaust (factory swaps- 04 750 exhaust), install NGK plugs, and a K&N air filter- this will be occuring soon. What else could I do to get the bike tuned up?
Thanks!
Nik

[Yellow]

The fuel gauge is not very reliable; it isn't linear at all and varies between bikes. On my bike the needle moves from the full mark to half full in ~80 km (~50 miles), but when it's really full it's about 5 mm past the full mark (takes about 70 km to move these 5 mm).

Calculate your MPG (by filling the tank totally and reseting the trip meter) to see if something is up with the consumption...

[The CyberPoet]

I was thinking the exact same thing... The sender info isn't linear and often varies from both bike to bike and sender to sender.

Cheers
=-= The CyberPoet

[CrazyMedic]

I hope that is what it is, still better than the Jeep thats for sure! I will watch it and see what happens. Thanks for the heads up on the guage.
Nik

[ThAzKat]

I too have the samething, I ride 53.6 miles to work. When I fill it completely full the needle will not move off the full mark for that whole 53.6 miles. When the needle does come off the full mark it moves faster the lower the needle gets. I can get 60 miles on a 3/4 tank LOL and at the end of that I am on the red zone.

[CrazyMedic]

UPDATE: Ok rode some more tonight- probably 50 or 60 more miles- just cruising around no racing, no high revving. Got down to the red zone on the guage and headed home. I stoped by the gas station so I could look into the tank. Sure enough, its almost empty (I can see the bottom of the tank, its that low). So either I didnt fill the tank up all the way or there is something wrong. When I did fill the tank I put in 3.6 gallons. Is there more gas that I can put in? Is there suck thing as putting too much gas in the tank (other than it spilling out?) Thanks for helping out a newbie!
Nik

[The CyberPoet]

Well, then here's a question. Are there more reliable gauge replacements out there? I thought you had mentioned something about having replacements Cyber, but I can't remember. Perhaps something with the low fuel light similar to the Busa?

I was working with LST on whether the VDO gauges would work with our senders, and came to the conclusion that without some electronic trickery on the sender signal, it wouldn't. The VDO specs for their two types of fuel gauges suitable for the Kat run either 10 Ohms (empty) to 180 Ohms (full), or 90 Ohms (empty) to Zero Ohms (full).

The 98+ Kat senders (and I'm guessing the pre-98's probably have the same values) are, at least according to factory spec:
Full tank: 1 to 5 ohms resistance
1/2 tank: 32.5 ohms
Empty: 103 to 117 ohms

Thus, in ThazKat's case (as an example), his resistance at the sender isn't dropping to below 5 ohms until more than a gallon is gone from his tank (the 56 miles he's talking about covering to work before his needle starts to drop). Unfortunately, there's no way on the gauge to recalibrate these values, so either you have to change the sender's signal (by putting in a resister somewhere into the wiring) or remapping the signal altogher (send it to a black box that create a "corrected" signal). I wish there were a couple simple screws on the gauge somewhere to reset it's range...

Cheers
=-= The CyberPoet

[KatanaO215]

when I had my Katana I would need to switch to reserve at around 120 miles. You were at 110 and didnt hit reserve yet

[CrazyMedic]

So I should expect about 150 miles per tank?
Nik

[Lagmo]

A full tank will keep me running for some 180-190 miles, but after that there's just fumes left
I usually refill at about 130 miles which is the bottom of the red zone on the gauge, but there's usually about 1/4th-1/5th still left in the tank(basicly the reserve). again; YOUR milage may vary

[NewRider]

Make sure that you aren't actually wasting fuel by checking your chocke assembly for stickage. If you are riding with the chocke on the whole time, you will waste fuel the whole time.

[wilson1]

Yeah, the gauges on mine say full, then when it finally starts moving, it moves FAST.

[md86]

Next time calculate your actual milage . I do that with EVERY tank of gas . Just fill it up , note the milage , ride for a while , fill it up again , and divide the number of miles you went by how many gallons it took to fill it again .

[Guest]

i calculated mine and it gets to empty in about 150 miles. i have 88 kat 600. i was wondering the same thing to. if its like this i rather drive my honda to school. just wondering what can be the problem....

[md86]

Yeah , 40's good . 30 kinda sucks . I get 30 when my bike's not doing so great (carb problems) .