TM 33/34 Mikuni flat slide pumper on stock bore (Big Bore in future)
#43
EDIT to above post - Airbox Lid does NOT have the snorkel, i know this does make a difference
KLXster, thanks for that tidbit of info. i am by no means a "tuner", this is the first time im actually tuning a carb properly and completely. with the CVK i just went by your recipes which were proven. the only other carb i "tuned" was a go-kart that i put a pitbike engine on. i thought i should start with the pilot system but what you said makes more sense. over the weekend ill put the carb back to "factory" settings and remove the lid. ill start over using the method you described and go down one size on the main jet to see what that does. also, if im understanding correctly, you're saying the main air jet is too big?
KLXster, thanks for that tidbit of info. i am by no means a "tuner", this is the first time im actually tuning a carb properly and completely. with the CVK i just went by your recipes which were proven. the only other carb i "tuned" was a go-kart that i put a pitbike engine on. i thought i should start with the pilot system but what you said makes more sense. over the weekend ill put the carb back to "factory" settings and remove the lid. ill start over using the method you described and go down one size on the main jet to see what that does. also, if im understanding correctly, you're saying the main air jet is too big?
#44
This ain't gonna happen quick. But following the correct procedure will speed things up - Establish a baseline setup, Fix WOT fueling first, everything else last..
I assume the above post is your baseline setup. You MUST establish a "FIXED" baseline setup and work off of it - no fooling around with lids, air filters, etc, during the tuning process.. If you need help in choosing a baseline, start with as lean a needle as you can with a clip setting at the top of the needle ( so that it is as long as possible when hanging down from the slide.) and a main
jet that is 2 sizes larger than the one in the above setup.. Know that if you only have one needle at this point in time, you will be attempting a
successful setup with that needle ( And in the future, you will find that it may or may not allow a successful end result.)
Be sure the accel pump / nozzle position and all other aspects of the Accellerator pump system is set correctly to what the TM peeps say to do - And they need to
chime in now or you'll need to research in here for the correct setup on the accell system. I think I remember something about the nozzle needs to point at the needle.
The main jet and MAJ "dance together" to produce a fueling curve.
With a given main jet, airbox setup, and air filter, the MAJ sizing will alter the fueling curve (larger = leaner | Smaller = richer)
Know that this "dance" is also in play with the Pilot Jet and Pilot Air Jet.
Post the results of your "new" baseline setup and we can choose the next tweak..
I assume the above post is your baseline setup. You MUST establish a "FIXED" baseline setup and work off of it - no fooling around with lids, air filters, etc, during the tuning process.. If you need help in choosing a baseline, start with as lean a needle as you can with a clip setting at the top of the needle ( so that it is as long as possible when hanging down from the slide.) and a main
jet that is 2 sizes larger than the one in the above setup.. Know that if you only have one needle at this point in time, you will be attempting a
successful setup with that needle ( And in the future, you will find that it may or may not allow a successful end result.)
Be sure the accel pump / nozzle position and all other aspects of the Accellerator pump system is set correctly to what the TM peeps say to do - And they need to
chime in now or you'll need to research in here for the correct setup on the accell system. I think I remember something about the nozzle needs to point at the needle.
The main jet and MAJ "dance together" to produce a fueling curve.
With a given main jet, airbox setup, and air filter, the MAJ sizing will alter the fueling curve (larger = leaner | Smaller = richer)
Know that this "dance" is also in play with the Pilot Jet and Pilot Air Jet.
Post the results of your "new" baseline setup and we can choose the next tweak..
#45
i know it wont be a quick process, as much as i would like it to be. the above post was my baseline but after reading your procedure it made sense why my adjustments gave me the results they did so im just going to start over. i dont intend to use the airbox lid, only put it back on so i can ride it and not have the AFRs go above 14:1 @ WOT. i have 3 different needles, 3, needles jets (P-4 P-6 P-8), 7 main jets (125-140), 4 pilots jets (10-17.5), and 8 pilot air jets (0.5-1.5 [?]). i couldnt find any main air jets, ill see if the PAJ threads into the MAJ hole. i know these will be very helpful to really fine tune the AFRs. the accl. pump is set to whats recommended by mikuni, although i THINK it comes in a tad too soon because the AFR drops to around 7-8 for a split second when i crack the throttle. i could be wrong though. the nozzle is pointed right at the needle
#46
You already know to disregard the AFR from the pump shot - kinda a no-brainer..
Now that I know your inventory, lets make some more choices for a baseline setup - I am guessing at all this, the TM guys need to step up to the plate in here.
Use the thickest needle out of the bunch, set the clip to the middle position.
As long as the needle will slide in and out of the needle jet, lets use the needle jet you have now - I do not know if there are needle and needle jet recommended combos.
We are not worried about anything Pilot circuitry related..
Edit: Also be sure to install a main jet about 2 sizes bigger than the one that made that horrible lean WOT AFR.
Now that I know your inventory, lets make some more choices for a baseline setup - I am guessing at all this, the TM guys need to step up to the plate in here.
Use the thickest needle out of the bunch, set the clip to the middle position.
As long as the needle will slide in and out of the needle jet, lets use the needle jet you have now - I do not know if there are needle and needle jet recommended combos.
We are not worried about anything Pilot circuitry related..
Edit: Also be sure to install a main jet about 2 sizes bigger than the one that made that horrible lean WOT AFR.
Last edited by Klxster; 09-12-2021 at 01:28 AM.
#50