Stalling when low on fuel

[Hoister]

My European (Norway) 2000 mod. 'Busa has a problem the mechanics have problems sorting out. It's working fine the first half of the gasoline tank. From there to nearly empty it stalls on me if I accelerate uphill, ecpesially if I click down the gears ('pardon my French). When there's almost no fuel left, I can't accelerate at all, it just stalls. It's not the model with the fuel pump recall. I used to have a "breakage" on the fuel-return hose, but that is no changed with no improvement.
Anyone heard about this?????

 

[jwcfbd]

Never heard of this happening but here's a few things to look at.
Not knowing the tank (if it is something other then stock)that you are using I don't know how it picks up the fuel. But if it uses some kind of hose inside the tank make sure it is all the way to the back. Not likely because most tanks use fixed stand off pipes but you never know.
Also check the the fuel lines going to the tank they might be kinked or pinched. With a full tank there might be enough pressure (weight) on the fuel to force it through the lines. Once the level drops there may be less pressure on the fuel allowing the engine to over draw the fuel supply. (pulling the fuel out of the line faster then it can get in.)
You might as check your fuel filter. It may be restricted.
I really don't know why you only have these problems while going up hill but hopefully this will help.

 

[JimGnitecki]

This really sounds like a restriction in the fuel supply somewhere, or a bad fuel pump. I had symptoms very similar to this years ago on a Honda CBR900RR that had a bad fuel pump.

The dealer's tech told me that the bike (the 900RR that is)would actually even run without the fuel pump if the tank was reasonably full, and would start screwing up when the level got below a certain undetermined level. When the tank is full, there is enough fluid pressure to feed the fuel through the system. When the level gets lower, fluid pressure falls, and the available fuel flow rate becomes marginal. Shows up first as a shortage when under load (e.g. climbing a hill), and then later, failure to run at all.

Same sysmptoms are possible if there is a partial bloackage somewhere in the fuel system. When you have lots of fuel (lots of fluid pressure), the bike will run. When the level falls, you starve the engine.

Jim G