My jet kit came in over the weekend and I installed the 152.5 main jet and left the pilot jet alone. I only had a chance to ride it for 10 miles or so. When cold, low speed is much better. When warmed up, sometimes I get pops when letting off the throttle to shift, sometimes I don't. I get an occasional pop on hard decel. I bumped up my idle and some of the pops seemed to have lessened, but I could be imagining things. I read about the test for the pilot jet, to run WOT and back off 1/4 turn to see if it speeds up, but don't remember anything for testing the main jet. I have a HD muffler with a 1/2 hole drilled in the baffle. Stock filter (which needs replaced) and no other real or imagined go-fast things.

So I guess I am pretty confused. I got the test backwards. Is there a test for the pilot jet?

The big one in the middle is the main, right? That is the one I changed and I didn't need to use my choke to get out of my neighborhood without revving the engine. But you said that shouldn't affect that.

Please put my head on straight!

I read that. It doesn't say how to test the pilot jet. Unless I am missing something.

Jetting without a dyno and proper air/fuel testing stuff, is a guessing game...

Experience,.. seat of pants testing,.. and inference...

You can get the main right with the 1/8th throttle drop... keep testing with bigger jets 'till the up-surge is gone...
Adjust your needle jet in relation to that,... roughly... if you go up a step or two on the main... reduce the spacer for the slide to 2/3... if you need more main,.. reduce the spacer more...
Adjust the pilot with that in mind also,.. but... the pilot is less critical, because you aren't stressing the engine at those rpm's... so, ere on the side of smaller with the pilot, as long as you can still adjust idle with less than 3 turns from full closed... This will help with gas mileage and won't hurt the engine or performance...

Maybe I should add this to the tuning post I did?.. ...
(I'm actually just realising that I contradict myself, somewhat)...
You should do jetting from bottom to top,.. because each step affects the next... idle mix, pilot, needle, main... additively...
...but, to get a base point.. I'm testing the main, with the throttle drop test... then adjusting everything below from there...
... but, once you make those changes, you need to test the main again...
Because, the pilot and needle have affected the WFO total...
I will make some changes to the tuning post...
I was stating proper procedure, as I have been taught... but, I realise now,.. that's not really what I do...

I say,..  ... test the main, then adjust the other circuits proportionally... then retest the main...
It ain't easy...
... and I judge my work, by observing how the bike behaves in humid weather, or at higher elevation... in those circumstances a well tuned bike, should start to pop just a little.. that's a lean pop.... and your well tuned bike should start to pop a bit when it's overly humid, or when you elevate more than 5k...

I'm sure I add more confusion than clarity.... Sorry...
Jetting is tricky... it's never right,.. just pretty good... even with pro equipment.. because the elements change day to day, and ride to ride...
...

Serowbot wrote on 07/09/12 at 18:25:18:



when i adjust the idle mix screw it seems to makes no changes to the idle at all? at least not as drastic of a change as the actual idle adjustment on the other side of the carb.

and 3 turns from full close? I thought it was three turns out from factory settings?  

OH, thanks for the heads up! ive been at three turns out from stock position for the past couple of days now   i hope that wont cause any problems with my carb!  :'(

FEW! (wipes forehead)   i thought i might of accidentally opened up a can of worms there!