I have 600 Cbr -95 (F3). Sometimes, when I accelerate the power cuts for less than half a sec about 3000rpm and then it continues accelerating normally. I've heard that valves can cause that kind of problem but the valves were tuned about month ago without any effect on that. It seems to do that randomly, some day 0 times and another day 20 times.

Anyone got similar problem or any suggestion were to look for the solution?

Thanks,
-Arto

 

So many things can cause the same problems ...anything from dirty carbs to dodgy electrical connections ... I would give her a good service, have you had the plugs out and checked them?? ... what about the fuel filter, it may be blocked or partially blocked, remove a float bowl from one of the carbs and see if it is full of a brown, slimy gunge, even a little will block your main and needle jets ... what about the electrical connections under the seat to the regulator and rectifier, do they look good and clean?? ...take them off clean and spray with wd40 or similar ... what miles has the bike got??

Check breather hoses and pipes for kinks or splits, mostly under the tank area, maybe they have become "pinched" ...as I say lots of things to check and work through....


Good luck and let us know

 

Ok, thanks for advice Bike has little over 60k km, which is about ~40k miles. Gotta check the carbs and el.connections some time soon when I got time for that. Fuel filter and plugs have been changed less than 3000 miles ago.

I let U know when (if) I get her well again

 

Well first off, check to make sure you have a fuel pump and that it works. I have the same problem and found out that it need the fuel pump to feed gas when it gets to a certain rpm or when you gun it. Not sure if this is the same for you, but when i'm rolling along slowly increasing power, it starts to sputter and lose power and then come back to normal once i give it more power. People told me it was the fuel pump and sure enough, mine wasn't even connected lol

 

It could be an electrical connection. A common one I've seen is the kickstand safety switch connector being loose, usually where it plugs into the wiring harness. Two of my buddies have had that problem. Good luck

 

Problem solved! (maybe)

I looked closely the cbr's air intake system and there were some solenoid valve that alters the air intake route. I read somewhere that it does operate at 20km/h (12,5Mph), which is just ~3kRPM at first gear. I simply disconnected that valve (electrically) yeasterday and she has worked perfectly after that.

I think the solenoid somehow causes an electrical pulse which interferes the spark system. The valve makes the 'click' sound when it's connected and I turn the key, so It's not totally broken. Next question: Is there any defects not having that valve connected? Is it "over 20km/h" or "under 20km/h" position now when it has no power?

Thanks,
Arsi