2010 FZ8s loose power/revs after a long ride

[Lucky Phil]

Hi guys, first post. I picked up a 2010 FZ8s a few months back. The bike is having a strange problem, that has happened on both the long rides i have done on it.

I go for a longish ride, about 200Km, stop for a couple of hours, then start the ride home again. 
After around 1 hour riding (speed approx 100Kmh) the bike will loose revs and will not accelerate. If i try to rev seems to intermittently rev then stop reving.
I pull to the side of the road and twist the throttle a few time and it seems to rev ok, then off I go for about another 30 minutes, then it will happen again.

I ride to work most days, doing 15 minutes at 60Kmh and around another 15 minutes at 110Kmh on the highway and have no problem.
 

Any ideas would be appreciated.

[Grahamm]

Welcome :-)

My first thought would be possibly the Throttle Position Sensor, but it's odd that it doesn't happen in day-to-day riding.

Still, get a copy of the manual and, if it's like the FZ6, you can put the instrument into Diag mode and check the TPS scrolls smoothly up and down the range with no skips or hesitations.

I know the FZ6 had a recall for faulty TPSs, but I would have hoped that Yamaha had learned from that...

[Lucky Phil]

Looks like the TPS is working correctly, via the diag mode. 16 to 99 smoothly.

I might try replacing the fuel filter and check the air filter.

Has anyone replaced the fuel filter on an FZ8 ?

[Gnasher]

Put the bike into diagnostic mode and check for codes. From what you're saying you appear to have an issue with the fuel system, probably a sensor. Could just be a bad connection or one is failing.

[unfazed]

Sounds like limp mode, Check the error codes and the coolant level. Could be overheating or a sensor breaking when bike is very hot. Probably not getting hot enough on the short ride to cause the problem. I have come across a few bikes doing what you describe when coolant was low.