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General Category => Maintenance => Topic started by: Tuneforkfreak on June 19, 2016, 10:20:31 PM

Title: Fuel level for reserve???
Post by: Tuneforkfreak on June 19, 2016, 10:20:31 PM
I was curious where the fuel level should be on my 1990 when it gets to reserve position? I'm thinking my reserve system does not function and was going to drain some gas near that point and do some testing and try to fix it. Also does it just shut off the fuel pump for reserve or how does it work?
Title: Re: Fuel level for reserve???
Post by: FJmonkey on June 19, 2016, 10:46:08 PM
My low fuel light does not come on, but I can go about 200 miles before looking for a fill station.
Title: Re: Fuel level for reserve???
Post by: moparman70 on June 20, 2016, 12:43:21 AM
my 86 would have about 1 gallon when the light fully comes on and stays solid red////  My 90 would only have about 1/2 gallon --- so I would say it varies a little.

86 works differently -- than the 90 but in principle they are the same the fuel is cut-off --- simulating you are on reserve and then when you hit the switch it allow the fuel to flow again --- 90 -- I believe must shut off the pump --- 86 closes the vacuum of the mechanism thus shutting off the flow ---
SteveCc
Title: Re: Fuel level for reserve???
Post by: Tuneforkfreak on June 20, 2016, 05:05:51 AM
Sweet thanks for the info. I'm going to assume that the fuel switch does something with the fuel relay??? Any info on that circuit would be much appreciated, like is it all ground circuit ?  When I first built the bike and was adjusting carbs and all that stuff, I think I had run into the issue of the low fuel/reserve but to be honest I had more than one thing going on at one time..... fouled plugs...... float levels.......etc ..etc.  Ive been scared to allow it to go below half a tank since then and Ive never seen the fuel light come on. Time to drain the tank and do some simulations, planning a ride with some friends and nothing makes you look worse in a crowd of new bikes than having an old bike that breaks down.
Title: Re: Fuel level for reserve???
Post by: Bones on June 20, 2016, 06:16:59 AM
The fuel light on mine starts shining when the fuel gauge is hitting the empty mark, takes roughly 16 litres to top it up from there, which leaves about 4 litres for reserve. To check if your fuel light bulb isn't blown, turn on your key flick the kill switch and press the starter button, the fuel light and oil level light should light up.
Title: Re: Fuel level for reserve???
Post by: Tuneforkfreak on June 20, 2016, 08:25:50 AM
Thanks man that's good info to know, I'll check the bulbs as you mentioned. I just pulled the supply line off the pump and as usual when I mess with this bike I get another schooling. While my bike does run to me what seems to be fine, it seems the fuel line is partially clogged. The gas is just trickling out of the line and when I tried to blow back through it I about collapsed a lung. I'm pretty sure the fuel should flow freely through that line and it may be the reason my first fuel pump had a short life? Draining gas now and will pull the tank when I get some weight off it, gonna take a while but at least I'm finding the issues.
Title: Re: Fuel level for reserve???
Post by: Tuneforkfreak on June 20, 2016, 10:13:25 AM
Here's my update, I removed the tank and found that the fuel line had came out of the metal retaining hooks under the tank and was pinched between the tank and the air box.......... completely my fault at last install. I first did as suggested and tested the fuel and oil light and they both worked fine. I then drained the tank and reinstalled it. I turned on the key and the pump ran (the fuel switch seemed to make no difference perhaps its been bypassed by previous owner or I have a different year fuel relay?) My fuel relay was missing when I built this bike and I acquired one among many other things. I put in a small splash of gas and the bike fired up, gauge below E the gas light slowly came on. I left it running and added gas and the light went out just above E. Seems like maybe I have a half gallon when the light comes on. Thanks to all you guys for being so helpful, you're awesome :good2: