Brief Pictorial Guide on Changing the Main Jet on our Carbs

Posts: 16

Im new here so if what im about to ask has areready been answered kill me.
I have a pro-kart wild kat 150 se I put the redneck uni filter on it along with a 18" harley muffler sounds greate.
What i would like to know is what size jets should i re-jet it to?
Roketa 150 gy6

Posts: 6246

Check the sticky in the engine clinic forum.

Posts: 167

Nice post and very helpful. Question

Which is the low speed adj and which is the idle adj. Idea

Posts: 38

a question...

i changed my jet with a "128"... but it doesn' seem to work ...

Anyway, my original gy6 150 cc comes with a "104" jet...
A new sym 200 cc come whit a "108" jet... (in Italy) so 120 or more

I'm afraid american (or chinese) jets got a different measurement unit from european ones... even if I believe it's almost impossible..

What did you find in your carburetor? Every you are running now whit a 120 or more?

Posts: 1677

Marco, was your engine running good before you changed the main jet?

Posts: 38

No, absolutely too lean.. whit the stock 104... even if it was running somehow...
Now (whit new filter and spark plug too) when i push the throttle... engine put off.

Ok, I need more fuel, but a diameter 128 has a section 50% bigger of my stock.. Shocked

I'we got a 120 to test too...
but I'd like to know if you had a 104-105 stock jet too.

If your carburetors come whit a 115-120 standard jet... and been upgraded to 125-130 now I got a huge surplus of fuel... and that 's the problem.
if you got the same mine, I've to hunt the gremlin elsewhere...

Rolling Eyes