Bike stops after 30 miles.

[Grindle]

Bike (Aprilia 650 single) starts instantly when cold, (reluctantly sometimes for some reason when hot) and runs for 30-ish miles. The tank was full before i set off.
Bike stutters and stops and will not re-start. Put it on reserve and the bike starts again and runs. I don't know what the tank holds, it does not look like the 4 gallons it says online but surely it should not go onto reserve after 30 miles?
Any ideas? I'm guessing the fuel tap has a mind of it's own?

[anonymous-user]

Blocked air vent in the cap?

Had that on my old R1. Died a couple of times on the north circular. I wasn't very popular.

[Grindle]

No it's not ideal stopping in heavy traffic in the outside lane. I will take a look at the breather and maybe see if there is a fuel filter though i can't see one.

[black-k1]

Partially blocked fuel filter? Lets fuel through slightly slower than the bike consumes it.

[alvington89]

I think Keiric has most likely sussed your problem.
If there is a vacuum in your tank then the fuel won't flow. Got to be a breather issue.

[SpeckledJim]

Does it have a crank or cam position sensor? These can sometimes work perfectly when cold but play up when hot.

[mygoldfishbowl]

How long does the bike run for on reserve, more than 30 miles?

I'd be inclined to pull the pipe of at the carb end and run the fuel on normal tap position in to a receptacle to see what happens. If the fuel stops or slows try reserve for the same amount of time and see if the same happens. At least you'll know it's a fuel delivery problem.

Could also be a larger piece of crap in the tank. what I've had before is crap swims around and will get drawn into the mouth of the pipe, but when the bike is stopped or on reserve the crap will leave the pipe opening until the next time it's sucked there again. The problem wont happen on reserve because there's normally a plastic filter thing which is a bigger area for the fuel to pass through than the small pipe opening so doesn't get blocked.

Edited by mygoldfishbowl on Saturday 20th April 15:05