I'm having a tough time with the jetting....

I'm currently running 160/165 dj,4th clip from top......and the plug is a pale tan color........I was running 165/170 and I had a slight stumble in the midrange at constant throtle...but it ran strong up top and on bottom........and if I was just hamering on it it would do good all the way through.....but when I held it steady in the midrange it would stutter.......

do you think I should jet back up and drop the needle down one?

 

What pilot are you running? The pilot not only controls the bottom 1/4 throttle but also puts a constant feed across the whole range additional to the needle and main jet which is contrary to many beliefs but true. I had the same stumble that drove me crazy until I went down one size on my pilot jet and then I was able to running bigger main jets which is what the bike ran best with and I got rid of my stumble.

 

27.5 pilot a 2 1/8 and 2 3/8 turns out.....

 

I would go to 25 pilots which will lower the constant flow across the range and then put the needle in the 3rd slot and then run the main jetting as fat as posible and then if needed fine tune it with the needle.

Feed that baby fuel on the top end and you see the results.

 

what would be the difference in tightening down the mixture screws and changing the pilots?

I had it at 1 1/8 and 1 3/8 with the bigger mains and it stumbled.......
but it was lean on bottom....the plug was WHITE after a long idle but the base ring was BLACK

 

The mixture screws only control the idle fuel flow and does not make a difference to any of the other fuel circuits but the pilots do make a difference because they will feed across the board additional to the other jets, so tighting down the mixture screws will make you lean at idle but have no effect anywhere else. I like to adjust the mixture screws to basically close to the turns you have but I do it by listening to the engine after you jab the throttle, it should come down to idge right away if it doesn't open them up abit, if the idle falls lower then normal after the throttle jab close them up abit.

 

aight.....thanx for all the help hiram!

what jetting did you run in yours?
we have almost the same setup.....

 

25 pilots 2 1/4 turns out the mixture with mikuni 190/195 main jets with mikuni needle at the 3rd slot from the top.

 

BTW I was guessing on the mixture turns since I had the motion pro adjusting tool and would adjust them by ear with the bike running.

 

The idle circuit works across every circuit BTW....not just 1/4 of the throttle range.