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

Check the sticky in the engine clinic forum.

Nice post and very helpful. Question Which is the low speed adj and which is the idle adj.

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?

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

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..

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...

So the jet that came out of my carb is stamped 114. I put the 130 jet in but its too rich, I put a 127 jet in and its not as peppy as it was with the stock jet. What can I do to restore the pep?

Could someone do a pictoral on how to adjust Hi-low and idle like this post? for after rejet....

I tried a 130 and had to go to a 125 then 122.5 to get the pep back.


My jetting has changed now due to recent mods.