03 FE400E Dellorto Tuning

Recently sold my 03 FE400 only to buy another. This one came fitted with a Big Gunn muffler which when repacked although a little loud wasn't to bad and has better power noticeably down low. I removed all the electric start gear as I couldn't get it right with my last one and they start so easy with the boot and it also makes jetting so much easier as the main and pilot and needle jets can all be done with the carb in place.

Now for my jetting wows, carb is 38mm Dellorto was 40 pj, 45 choke, dr270 nj and k51 needle on clip 3 and 4mm slide 180 main. I had a noticeable fluffly uneven spot on the midrange which only ocurred recently and it was a bit rich on the bottom.
I have followed the steps from the doc and gone to 4.5 slide, drilled air jets to 1 paj and 1.4 maj (didn't have a 1.5 drill) 35 pj 45 choke k51 needle but still have the DR270 nj and 180 mj. Low end response was great but the fluffly spot was still there, I checked the spark plug and it was looking whitish or lean. I took the needle clip to the lowest point which seems to have helped the midrange but now it seems choked up high. Is the DR272 a richer needle jet as it seems I need to be richer on the needle and leaner on the main. Do you think I am on the right track ?? Lastly does anyone know where I can get the parts here in Australia as the berg dealer said the NJ would be 4 to 6 weeks and around $45.

Also bike is backfiring with occasional flames from the muffler on deceleration, I figured this could be caused by an air leak at the muffler flange.
Sorry for the long post.
Dan

Taffy I thought the main jet was rich as became worse after lifting the needle (lowering the clip) also its not really flat more blubbery. Will try the KTM dealer today and see what he has but if also a long wait may grab your spare NJ. Do you take paypal ?
Could anythig else have bought on the midrange problem as bike was running good up until after a fairly long family ride that was mostly slow very low end riding in 1st 2nd and 3rd gears.
Thanks Dan

Taffy Thanks, tried a 165 main jet today and didn't change much so i put in a 190 and its heaps better. I will source the 272 NJ and try that when it arrives .
Dan

So heres how it ended. Bike cleared up in the midrange and top end with the 190 main, but was running on ocasionally when I backed off the throttle. I got the new DR272 and fitted it with along with with a new K51 needle and went up a size on the pilot to a 37 but the running on problem remained. When i backed off the throttle from low revs it would continue to idle high for a couple off seconds before returning to a normal idle. I finally took a standard 4.0mm slide from another carby and fitted and now its good. Final jetting Needle K51 on clip 3from top, NJ DR272, MJ 185, PJ 37, Choke 45. I wonder now if I had gone back to the 40 pilot and left the 4.5 slide in ther if that would have cleared ir up as well.
Cheers Dan