Did 100 miles bike ran really well apart from speedo playing up 7 days ago. Over the next few 7 days I started the bike up few times while I was while I was diagnosing the Speedo issue. Went to ride it today and the bike is misfiring and lakes power. If I hold it at say 3000 revs when stationary the revs start going up and down. Any suggestions please thanks. When riding the bike if I tried to accelerate the bike goes into kangaroo mode

Have you replaced the fuel filter and also it is possible the ignition switch needs cleaning.

No I haven’t done anything yet where is the fuel filter?

Inside the tank, do a search of the forum and you will find many threads about changing the fuel filter.

I have a spark on all 4 plugs and I have reseat the ecu is there a way of checking to see if there is a fuel blockage

Click on the PORTAL tab and then Tech Page below the blue/yellow moto and then agree then the very first item is how to replace the fuel filter. 
When you get a new to you K assume that no maintenance has ever been done.  Replace all fluids and filters as a minimum.

I have ordered a fuel filter