Cutting out at cruising speeds

Tacho D

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Only yesterday, for the first time this F650 twin was cutting out at low throttle settings at 50mph. When twisting the throttle to accelerate, it would suddenly restart and pull. It starts without problems and idles smoothly. Only done 9500 miles and there is no indication of the fuel filter being changed. Maybe time for a new one? It is probably 18 years old.
 
How full was the tank? I imagine it was pretty warm yesterday. Low fuel level in high ish ambient temperature can cause the fuel pump to cut out. There is no separate fuel filter by the way, just a strainer on the pump pick up.
 
My initial reaction was the same as @thomo57 - sounds like the fuel pump/controller. Presumably no warning lights showing? Most owners learn to keep the fuel level high, above half way, in hot weather. The battery needs to be in good condition too. making sure the terminals are snug - the giveaway is usually the clock resetting.

However the bike has obviously stood around for most of it's life, with the fuel system full of corrosive stale hydroscopic fuel, so the problem could be elsewhere. IIRC we've even had similar symptoms reported, when it was simply the rear brake binding & another when the bike was dropping onto one cylinder.

Rather than guess though, it maybe best to get the codes read first.
 
My initial reaction was the same as @thomo57 - sounds like the fuel pump/controller. Presumably no warning lights showing? Most owners learn to keep the fuel level high, above half way, in hot weather. The battery needs to be in good condition too. making sure the terminals are snug - the giveaway is usually the clock resetting.

However the bike has obviously stood around for most of it's life, with the fuel system full of corrosive stale hydroscopic fuel, so the problem could be elsewhere. IIRC we've even had similar symptoms reported, when it was simply the rear brake binding & another when the bike was dropping onto one cylinder.

Rather than guess though, it maybe best to get the codes read first.
I thought the same. Had similar issues with an 09 plate 800gs. In my case reading the runes didn’t help. Buying a fuel pump and FPC from Sherlocks was the answer.
 
How full was the tank? I imagine it was pretty warm yesterday. Low fuel level in high ish ambient temperature can cause the fuel pump to cut out. There is no separate fuel filter by the way, just a strainer on the pump pick up.
Yes, just under half, and very hot too. I did however see mention of a filter attached to the pump assembly, U-tube video on replacing it. Motorworks stock it, I ordered one.
I thought the same. Had similar issues with an 09 plate 800gs. In my case reading the runes didn’t help. Buying a fuel pump and FPC from Sherlocks was the answer.
Are there any links to that? Might be worth a try if nothing else works.
 
Strange, how opening the throttle full seems to restore supply. And it would then run at high speeds. Might be worth removing the assembly and siphoning off the contents from the bottom of the tank to check for water/gunk.
 
I had this on a 2014 F800GT, unnerving, had to pull over and check through connections back to the battery, nothing found and didn't happen again before I traded it in, but weird, like the kill switch had been pushed
 
I had this on a 2014 F800GT, unnerving, had to pull over and check through connections back to the battery, nothing found and didn't happen again before I traded it in, but weird, like the kill switch had been pushed
That sounds more like the side stand switch to me.

The OP appears to have a fuelling issue, but he has embarked on a fix based on his original assumption. Let's hope he guessed right, otherwise this will start to get expensive.
 
How full was the tank? I imagine it was pretty warm yesterday. Low fuel level in high ish ambient temperature can cause the fuel pump to cut out. There is no separate fuel filter by the way, just a strainer on the pump pick up.

There is a fuel filter , I’ve changed it on F650/700 and 800 twins

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Sent from my iPad using Tapatalk
 
Interesting, I stand corrected. The pump arrangement is basically the same as the 1200, which does not have a filter like that one.
 


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