Miss at high revs

[08nzrocket]

My roadster has developed a miss at revs over 5k in 4th gear...originally it had a miss in the early gears(2 or 3) and the technician reset the throttle position sensor and the balance injection was slightly out and test ride was good and now it rides snatchy)the miss is apparant at around the 200kmh zone (which isnt there at the average test ride)
The technician has pulled the plugs and all appear to be burning a lovely brown colour and the vacuum hoses all seemto be clear and no fault codes are on the computer
So my question to you all is what may be causing my misfire

 

[Mittzy]

Your license might go missing if ya get caught!!!
Coil leads maybe?

 

[HansO]

When was the fuel filter changed, while changing it I would suggest an ultra-sonic clean of the injectors as I have found that the filters allow ultra fine particles to get thru and slowly block the very fine holes in the injector pintle which disrupts the spray pattern

 

[Rocket Scientist]

Your license might go missing if ya get caught!!!
Coil leads maybe?

I have also heard of the low tension leads becoming loose or corroded. It has been suggested to unplug them, clean them up and then pinch them slightly so they fit snugly again. Others swear by a coating of die electric grease before plugging back in as well.

P.S. Use caution running it in the "missing" situation. The super charged Buick Riviera I used to have started missing at high rpm. While trying to diagnose it I burned holes in two of the pistons. Turns out it was leaning out do to a fuel issue. To late smart.

 

[Cruzn6]

My roadster has developed a miss at revs over 5k in 4th gear...originally it had a miss in the early gears(2 or 3) and the technician reset the throttle position sensor and the balance injection was slightly out and test ride was good and now it rides snatchy)the miss is apparant at around the 200kmh zone (which isnt there at the average test ride)
The technician has pulled the plugs and all appear to be burning a lovely brown colour and the vacuum hoses all seemto be clear and no fault codes are on the computer
So my question to you all is what may be causing my misfire

Had a similar situation on my 09 Touring..It would hit a flat spot between 60 and 70 mph...After 3 visits to the shop, new TPS, and some adjustments, they changed the stepper motor, and it all went away..I'm not saying that's you particular problem, but it solved this issue......

 

[08nzrocket]

Thanx for the ideas this will definitely give me somewhere to start ...but what is a stepper motor and what does it do?

 

[Cruzn6]

Thanx for the ideas this will definitely give me somewhere to start ...but what is a stepper motor and what does it do?

It is out in plain view right under the throttle bodies towards the front of the bike...Black box with an electrical connection running to it..I believe it's main purpose is to control the idle, but it solved my particular problem.......I'm not a mechanic by any means but just trying to help......By the way, I traded in the Touring for a 2014 Roadster which is sitting in my garage waiting for the snow to melt!!.........Larry P.