Two wheels good.

[Hooli]

I'd start by dropping the fuel tap out of the tank & stripping that down. They've got a pick up filter & if it's like the ones I've done just a ball that moves over holes so could easily block.

[bub2006]

I'd be leaning towards ignition component getting hot and failing.

[Jerzy Woking]

I'd be asking https://www.fjownersclub.co.uk/about-us
particularly Phil.Hacker who has been racing and servicing FJ's for years.

[Hooli]

I'd be leaning towards ignition component getting hot and failing.

That's another good option. I was just assuming MM was right about it being a fueling issue.

[bub2006]

I'd be leaning towards ignition component getting hot and failing.

That's another good option. I was just assuming MM was right about it being a fueling issue.

I'm going with it having a rhythm of sorts. 10 mins running 5 mins stop. Usually fuelling is a bit more erratic in my experience

[marvinsmom]

the other half has been looking on the FJ owners forum and it has been suggested that the petrol tank vent maybe blocked or at least constricted.

k says that the bike will fire up and run happily, then once underway it just looses power more like its not getting sufficient fuel. then it wont go but then will run happily again after a wait. so next time the bike comes out we are going to try it with the petrol cap loose to see if that helps.

also the guy at the local motorcycle garage has decided to go away from the general maintenance side and go to fabrication and the like. i guess it pays better and if bukes are anything like cars are, then getting spares might be an issue. the guy who does alot of out car maintenance has been having loads of trouble getting bits even for common cars, and has been told by i think Andy Page's that if its for a car older than 5 or 6 years old then they don't stock bits for it!!

[Jerzy Woking]

My 125 scooter had a similar issue. Turned out the tappet on the inlet valve was tight, and got tighter as it heated up, so would not restart until it cooled down and the gap opened up.

That won't be with your 16 valves on the FJ, but always something to bear in mind on small singles.

[DodgeRover]

Vacuum operated tap, possibly with a clogged filter? The tank vent is a very good idea too, if she runs it till it stops then opens the tank and there is a big hiss of air going in then that's it.
Had it had a lock set fitted? It's probably possible to get a pattern cap without any vent..

[Hooli]

Aye thank vent is a good one, very easy to check too after all.

[xtriple]

I did a load of work on a guys scooter that did the same and he reckoned it was ignition. I changed lots of it with zero success, that was the tank vent which I sussed the first time I actually rode it and fixed it in ten seconds.