Flat spot at 6K revs

[steved]

I have noticed recently that my CBR has developed a flat spot around 6,000 revs. Below and above 6,000, good linear power. The spot seems to be present in all gears, and coincidently, happens to be the revs I do cruising in 6th gear.

Any ideas on what may be wrong and how to alleviate this? Dirty plugs? Dirty air-filter?

Cheers

[kiwi cowboy]

I have noticed recently that my CBR has developed a flat spot around 6,000 revs. Below and above 6,000, good linear power. The spot seems to be present in all gears, and coincidently, happens to be the revs I do cruising in 6th gear.

Any ideas on what may be wrong and how to alleviate this? Dirty plugs? Dirty air-filter?

Cheers

not sure i can help but is iy carbed or injected and how many k's has it done

[racefactory]

Isn't that a natural carburation problem?

All my VFR400's (carby) have had this problem, but at 5k.

[steved]

not sure i can help but is iy carbed or injected and how many k's has it done

Carbed at 88,000 km.

[steved]

Isn't that a natural carburation problem?

All my VFR400's (carby) have had this problem, but at 5k.

Carby is a good theory as the engine also runs on 2 cyclinders some mornings when it is cold.

Time to rip the engine apart and get me nails dirty.

[Evilgenius]

My bike did the same at about 9k rpm, i used a petrol additive to clean the carbs and she is better again, just give it a shot before you spend more time and more money on the nig stuff

[F5 Dave]

Check out the factorypro site & hunt around on it. Sounds like worn emulsion jets, but a general service is always a good start.