Jets

[09agility50]

I was curious of the main jet size(thread size). Also where is a good place to purchase them?

[Bray0671]

I got mine from my dealership along with the smooth boss is was 10$ for both. But my A hole dealership made a note on the receipt that is was derestricting the scoot my self 

[09agility50]

My scooter came with a bigger jet and smooth boss so i put them in after break in. My last project was the NCY cvt kit. I just recently purchased the 72cc BBK and was wanting to play around with a bigger jet when it gets here.

[Bray0671]

Nice did you have big improvements with the cvt kit

[09agility50]

Yes i did like the improvements of the cvt kit, but i didnt use all the parts it came with like the springs in the secondary and the roller weights. I did a lot of testing with all the parts. Hopefully i can use those stiffer springs and different roller weights when the 72cc kit comes.

Any way the CVT kit does show improvements.

[09agility50]

So back to my first question. The only thing i can find is M4x0.70 Threads. Does this sound right to anyone?

[mono]

Nope : 4x0.70 is the standard metric coarse thread, which is exactly the type used in most cheap chinese Keihin-immitation carbs for the 139QMB engine... The standard Kymco carb has a thread that's closer to M5 (but isn't)...

You'll need a jet that's specifically made for a Kymco carb.

Only if you can't find one of those, you could try the Dell'orto small type jets, these will "fit with a bit of spit"  
Be careful though, it's possible to ruin a carb with the tight fit of these jets...

[09agility50]

any idea were to purchase them online? i have only found up to 85 size. Im looking for upper 80's maybe even low to mid 90's.

[mono]

What's your setup ?

Did you install a big bore kit or a free flow air filter ?

[09agility50]

I have the BBK and filter on the way. I was wanting to get the jets also that way when i am home over thanksgiving break i can mess with it when i install the BBK. There isnt really any local dealers or parts stores to get the jets is why i was asking about online.

[mono]

What kind of BBK did you order ?

[09agility50]

72cc

[streido]

You want keihin M5/5mm threaded jets for the stock carbs 

[skippy]

i think the last american person thet asked got some from stadiamyamaha.

[mono]

For a 72cc I would start with a size 88 jet, you can always go down to 66 if 88 is running rich...

Edit : unless you really want to use the free flow airfilter instead of the stock airbox, that is : with a free flow filter you'll need a way bigger jet, but you're pretty much on your own then, since they're all different... My advice : keep the stock airbox, on a 72cc with stock carb, those open filters are not worth the trouble they cause...