I have a 2008 terracross 800, I now live in Thailand although I am English.

On First starting the engine runs fine but after around 15 minutes I am suffering power loss in high range. It will only pull about 40 km an hour on a flat road.

It has a new fuel filter, the symptoms are very similar to fuel starvation in my, opinion.

Can anyone tell me if with the pipe taken off the fuel filter and ignition turned on should the fuel only flow for around five seconds and then the pump stops? I would have thought the pump would only stop when the pressure builds up? And should run constantly with the pipe disconnected and put into a fuel can ?  Unfortunately, I do not have any equipment to test flow and pressure, but the flow is very good for the five seconds. The pump is running.