Question regarding the reserve position on the petcock

exactly when should i be using this? i've got a '81 kz 440ltd and this afternoon i was on a long ride....the longest i've gone with my bike. after running it for a while at 60mph it started to die out and wouldnt respond to the throttle. seemed like i was running out of gas and stalled. when i pulled over and checked the tank it was prob 1/3 full. it started right back up again but it made me wonder about the resreve on the petcock. why not just always keep it in that position? can anyone answer that?

del

Dubzie111 wrote:

exactly when should i be using this? i've got a '81 kz 440ltd and this afternoon i was on a long ride....the longest i've gone with my bike. after running it for a while at 60mph it started to die out and wouldnt respond to the throttle. seemed like i was running out of gas and stalled. when i pulled over and checked the tank it was prob 1/3 full. it started right back up again but it made me wonder about the resreve on the petcock. why not just always keep it in that position? can anyone answer that?

Without having an automobile type fuel gauge on the motorcycle, the petcock reserve position is to allot the final quart or so toward making it to the next gas station.

Should not have hit reserve with 1/3 tank remaining. Might be a clogged vent in the fuel tank cap causing fuel starvation. Easy to check next time it happens. Just open the fuel cap and try running with the fuel cap left remaining open (not snapped closed).

As to why not always keep it in reserve position -- most of us have been unceremoneously reminded at one time or another by having to push instead of ride to the next gas station. It should be SOP when filling the tank to assure the petcock NOT being left in RES position (at which time I also habitually run the tripmeter back to zero).

Good Luck!

Your petcock has two fuel pickup tubes inside the tank. One is higher than the other. The higher tube is the normal ON or RUN position. The RES position is the lower pickup tube. There is no reason you couldn't keep the petcock on the RES position except if you tank is full of sediment and in this case, the lower pickup would be more prone to picking up the sediment. The purpose of the this upper / lower tube arrangement has already been described (to help you keep from running out of gas) but keep in mind that you will need to DISCOVER how much gas you actually have in the reserve condition. If you use an aftermarket petcock like a Custom Chrome as sold by www.z1enterprises.com , there is less than 1 quart (as somebody claimed)... I KNOW you can't go a full 5 miles on reserve with a Custom Chrome as I have pushed the bike a couple miles when doing an experiment to see how much gas was still in the tank on reserve. Also, my KZ900 tank is supposed to be a 4 gallon tank. It will actually hold 3.8 gallons of tank after running out of gas and you can hear a little gas still sloshing when it is fully out of gas. Some gas will just not get to the petcock.

I think the best way to judge how much gas you have in the tank is to reset the trip odometer after fill up. When I see 100 miles on the odometer, I start looking for a place to fill up...