Hi all, any advice greatly appreciated with my CBR 600 f4 year 2000.

Starts, drives idles ok hot or cold at slower speeds. But if I try to go past 50-60 mph at all it completely loses power to the point it feels like it's cutting out. Once slowed down it will then ride ok again. Pretty much impossible to ride on a motorway as it is. If I drop down gears to get the revs above 7k it will pull but it's very hit or miss.

Any pointers on where to start checking first? Carb related? Reg rec?

Thanks

 

Try the fuel pump. Sounds like it has enough fuel at lower speeds but not feeding engine when it needs it. May also be the fuel relay.
Good luck.

 

Thanks for you reply. You're right it does feel like fuel starvation. It's like flicking a switch, it just dies. Pump looks like it's been on there since new (2000) so will look at changing it out.

It idles starts and runs at low rpm and speed as it should.

Charging system checked all good. Stator and r/r bang on figures.

 

woah woah woah, dont just start changing parts because they look old. the service manual has a step by step process to testing if the fuel pump is bad. how many miles are on the bike? it could also be junk in the carbs and maybe they just need to be cleaned.