(Carbed) CBR600 flat spot/hesitation

[singlesman]

I’m with Tricky and ‘The big cheese’, had exactly the same symptoms on our R1.
Turned out to be ovaled emulsion tubes and the tips eaten away on two of the dynojet needles. (They do a free replacement service if you send them the old ones) what I thought was a lean mid-range was actually the complete opposite
But as others have said, start with the simple stuff.
Cheers,Paul.

[singlesman]

Just thinking after reading Taipans post, not sure if you’ve cleaned the K&N filter but a good mechanic/tuner I know told me that if they are washed out and then oiled before they’re absolutely bone dry then moisture ends up getting trapped, making them very inefficient!
Just a thought.

[Mr. Dazzle]

Really can't be arsed with stripping carbs. This is supposed to by my reliable bike to go with the nightmare old Brit Iron.

Needs must!

I could just ride everywhere at 9000rpm / 100mph

Will you do it for £450 kfb?

[Ssray]

Cbr f3 or fx? Std exhaust? The dynojet kit is supposed to help on the fx, mine was a bit of a pain but swapping the front sprocket for a 15tooth one helped, the flatspot was still there but you had the torque to pull through it a bit better

[Bigyin]

My 600 Fazer does exactly the same and i think its probably down to the main jets in the carbs as it pulls cleanly right up to the point where the main jet kicks in. Doesnt bother me that much as i use it for a work bike with most of it teaching novices on 50's and 125's but even on DAS training on 600's it isnt an issue. Only has an issue when i am on my own and want to crack on a bit and get a bit pissed off mid overtake when it dies and down shifting makes it hit a brick wall.

I also know the Fazer has an issue with the rubbers on the carbs to the airbox starting to harden and crack which can cause issues

[Mr. Dazzle]

Cbr f3 or fx? Std exhaust? The dynojet kit is supposed to help on the fx, mine was a bit of a pain but swapping the front sprocket for a 15tooth one helped, the flatspot was still there but you had the torque to pull through it a bit better

Yeah stock Honda exhaust, it's an F3. It's got stainless downpipes but they're not performance enhancing I don't think, they were just to get through the MOT. It's also got the actuated idle circuit disconnected so it always runs on the main plumbing - but that shouldn't make any difference at 7000rpm anyway.