My brother is on a trek through north and south america and is reporting that the bike sputters and dies occasionally.
symptoms: after the first occurance he looked down and noticed that the fuel filter was empty and once he stopped it filled again.
he switched to the reserve position and the bike started right up. he was at an altitude of 2000 ft.
I suggested the problem was a restriction between the fuel filter and tank on the main supply line and recommended closing the fuel supply valve at the tank and running the bike till it died, then taking the hose off the backside of the filter, open the fill cap, and blowing on the fuel line while opening and then closing the supply valve. AFAIK he did not do this.
he bought some fuel system cleaner and put it in the tank, and the problem is still occurring but now is happening with the supply valve in the main and reserve position. He says it only starts when choked, and last I talked to him, he had it started and was continuing on toward San Francisco.
Any local riders who can help would be awesome.
Just talked to Taylor and I guess the vapor recovery gear they have on the gas pumps in Cali has been keeping him from filling all the way, and he is running dry before he expects to. At 132 miles in each instance to be exact. filling up and moving on. he's 90 miles north of sanfran
Fuel starvation of some kind is my guess. A partially clogged fuel filter could potentially cause issues like that.
Has he checked anything else out besides how to make the bike go further?
Is this an older single-cylinder F650, or the newer twin? The old F650 had a really lean fuel map and they often suffered from hesitations, stalls, etc....especially on ethanol laced fuels. One friend of mine bought a Paris-Dakar model and took it to the dealer several times to get the bike fixed to no avail. He was about to sell the bike when he had the chip reflashed by a third-party vendor and cured all the bike's ills. He still has it all these years later!