Super 9 AC Jets?

[19krevs]

Hey guys, I've been looking into buying a new pipe and rollers for my scooter and before that I wanted to make sure I could get the main jets I need to up-jet. I used the search function and found this link to some ->
(http://www.jetsrus.com/a_jets_by_carburetor_type/jets_keihin_99101-116_main_round_small_and_38-xxx.htm)

but I'm still pretty confused because my jet looks like this, it reads M75 which I'm guessing is the jet type (main) and size.


any advice what would be good, I'm still using the stock airbox too, would I need to mod that?

note: I own a sting 50 not a super 9, but they do have the same carb, engine, exhaust... etc, the sting isn't listed on any sites so its easier finding parts under the super 9 AC name.

wicked forum by the way //this should have been posted in the super 9 category, sorry.

[TLRam1]

Your main jet on the end should unscrew from that housing.

[wordslinger]

Welcome to th' Forum, 19krevs!!

                   

TLRam1 is correct...flat screwdriver in it's slot and hold the housing with a wrench...threads out counter-clockwise if looking at the slot...

Also, the People and Cobra share the same carb...PB-16

..the M75 is indeed the OEM main jet size... translated to .75mm opening in the jet...

[wordslinger]

..As far as the airbox is concerned, that's a matter of choice..

..some people drill holes in it, some leave it as is.. Some (me) simply replace it with a good quality free-flow filter.. It's not necessary to mod it at all with an aftermarket exhaust, but if you do replace it, it would be prudent to raise the carbs needle in order to keep the fuel mix tight during mid to full throttle...

..the PB16 carbs do not have adjustable needles, so you have to add a @ .025" washer beneath the needle's head, and shave @ 15- 20 thousandths off the needle retainer clip... kinda major mod, but I swear by it!


 

[19krevs]

thank you for the help! I tried unscrewing that from the housing during my first inspection but it was rather tight (don't really want to break anything since its my daily ride to school and stuff). I think I'll leave the airbox for now as well, seems like a bit too much work just yet. Keep it safe with one mod at a time I guess, cheers again guys.

[wordslinger]

..yup, if you don't change the airbox,, you can jet and roller-tune much easier...

..the key to adjusting roller weight, is maintaining a constant rpm within your pipe's powerband..

..keep rpms within a cpl hundred throughout acceleration, after any initial stall,

..my s9 holds 83-8500 from take-off up to @ 53 mph, then continues up to around 9100 around 62mph...

[wordslinger]

..the rule of thumb is that 15% increase, in my experience in jetting, is a good starting point...

..have 12 and 10 percent jets ready...maybe an 82 or 85 to start...

..do plug chops at idle speed, adjusting mix screw for a good idle mix...

..without changing airbox, you should then be able to chop at full throttle...

..depending on your altitude, I'd bet no less than an 80 will work well..

.. a little rich is safer...