Originally Posted by DFlanagan
Alright Goat I'll look into the needle and atomizer. As of now i don't have much faith in that 21mm carb. I had nasty hesitation on acceleration and it ran super rich. That was after I swapped all parts from the 19mm to the 21mm (with the needle position all the way down, leanest position). Then I swapped all the parts back to the 19mm carb with the needle position all the way down and it ran great.
I don't understand how opening your carb intake diameter by 2mm would cause this problem? I'm calling Motomx.com today to see what's up.
That 2mm is worth it to me. It is much more than 2mm. When you look in the rear of a 19mm, then the 21mm the rear is way bigger It definitely breaths more letting more breath in that motor..
Currently on my 21mm, 258 AU atomizer and W7 needle combination I run at the third notch up ''richer'' with a big size main jet. Around a 97. My dynamic between lower throttle and wot is very smooth with no transitions. So what have I changed here lol.
You got a ''richer'' 262 AU atomizer with a richer running W9 needle. The only way it will run is in the leanest position. This effects lower throttle performance big time in my experience at my high elevation. I never found a magic chart that told me where I was or where to go ether. Wound up trying parts till it made sense.
Swapping out jets never fixed it.
Try my set up and go from there I am absolutely convinced it will get you closer than you have been yet in this tuning deal.
Keep playing with those stock sea level parts! Your getting closer! That's what I did! It was brutal
Lemme say it this way for ya, I systematically tried ever combination there was. Until you change out the atomizer,choke jet, Needle, etc. IMHO I am convinced you will stay disappointed. Us guy's at a higher elevation simply cannot use stock sea level gut's in these PHBG carbs with the Morini IMO.. Atomizers Choke Jet and the like. There is no stock PHBG carb with sea level guts that ever worked right for me at my elevation on these Morinis.
Had that bucking and hesitation at take off annoying big time,but could get excellent wot response. All this was at the potential expense of leaning out a main jet. The bike still had race worthy power but was not tuned right yet.
I did however find a flawless cure..
Got's 4 PHBG carby's sitting here. They are all the same. Save two are 21mm's. The stock sea level parts swapped from a 19mm does not cure a 21mm here ether.
There could be more in the picture with your big bore kit? But I really seriously doubt it..
PM me or gimme your phone number.? I will try to clearly explain it for you? With a breakdown of what every part in this said jetting means? What it meant for me. I really do wanna get you get set up!!!
Prolly got a small fortune is your hog. I racked my brains on this one and got it figured out! That 21mm should be absolutely kicking butt... They are finicky carby's and IMO your jetting is not close to right.
Now back to our speed thread!