Fuel Problem need HELP

[Pat Mcrutch]

The problem was when we went for a ride the other day the bike ran fine till it got down to about 1/4 of a tank right on 300k's, (Been that low before), it started to loose power then onto 2 cylinders so pulled over and turned it off after a few min's tried to start it but rough and on 2 so sat there for about 15 min's then pushed it to top of the hill (not far thank heavens) rolling down I clutched it and onto 2 for a bit then onto 4 and never missed a beat till we got to town 60k's away  fulled up been fine since, it was a very hot hot day.
Any ideas on what the problem maybe and how to fix it, I've only had to bike for a few months so I've ordered fuel & air filters.
Wayne   

[Gadget]

Wayne. 1100 or 1300?

[Brock]

The next time it happens, try opening the fuel cap and see if that helps. some times a vacuum builds up in the tank, so fuel cant feed.

[Gadget]

Old vehicles used to get "vapour locks" in the fuel line on hot days.  The fuel would turn to vapour, and this prevented the fuel pump from getting suction.

[StinkyPete]

The next time it happens, try opening the fuel cap and see if that helps. some times a vacuum builds up in the tank, so fuel cant feed.

To prevent the vacuum as fuel s consumed, there is a breather hole that you can see on the left side underneath the fuel cap.   Squirt a bit of RP7 into the hole and blow a puff of compressed air down the hole.   If the RP7 runs out of the breather hose under the bike, the breather is OK and no vacuum should occur.

[Pat Mcrutch]

Sorry it's an 1100, and I did release the fuel cap but did nothing

[Brock]

My bike did that a couple of times. After the engine has died, it takes a little while to get started .

The problem may lie in the vacuum operated fuel shut off valve. Bypassing that can help. Sometimes they develop a pin hole leak in the diaphram so the valve shuts off. Usually happens when overtaking, or sitting at 110 Ks on the freeway when in the middle lane. I.E. at the most inoportune time.

[Pat Mcrutch]

Thanks for all the replies, I've taken them on board, at the moment I'm waiting for fuel and air filters to arrive then I'll take it apart and do it all at once I'm hoping one of these things are the problem as I'm thinking that if it's the fuel pump being the problem like most of the net sites say it's going to be very costly.
Wayne

[Biggles]

Thanks for all the replies, I've taken them on board, at the moment I'm waiting for fuel and air filters to arrive then I'll take it apart and do it all at once I'm hoping one of these things are the problem as I'm thinking that if it's the fuel pump being the problem like most of the net sites say it's going to be very costly.
Wayne

It's not all that difficult to access and there are second-hand ones around.

[Brock]

The simplest thing to try is the vacuum switch bypass. Costs nothing, no parts needed.