flat spot at 6k rpm

[Rema1000]

I had been having problems with the bike killing at idle, so I reamed-out the pilot jets, I now have a major flat spot just under 6k RPM.

It's mostly noticabe in 6th, once in a blue moon in 5th, and never in 4th or below.  If I'm on the highway at (say) 5500rpm, and just slightly add throttle, sometimes the bike will bog; today, it even chugged once, like it does when you're running out of gas.  If I hold steady throttle once it bogs, it just keeps bogging, slowing down.  If I roll-on harder, then it spins-up again and starts to accelerate.

Very odd.  Think I might put in fresh pilot jets, just to start with a clean slate.  These have been drilled-out a couple of times.

[davipu]

interesting, you thing it may have anything to do with your choice of fuel?

[scratch]

Shim up the needle.

[Rema1000]

Yes, the fuel could have something to do with it: because the jets are oversized by 40% an 30%, but the needle is stock.   It's always had a bit of a flat spot at 6k, but since I reopened the pilots and sync'ed recently, it got much worse.  

I thought that the needle shimming mostly helped richness "off the line", not when doing mild acceleration at 55mph in 6th.

[mjm]

[quote="Rema1000"I thought that the needle shimming mostly helped richness "off the line", not when doing mild acceleration at 55mph in 6th.[/quote]

Raising the needle richens the mixture as the slide rises out of the emulsion tube - almost no effect just off idle - it mainly has an effect on the transition from part to full throttle,