169fmm jetting carb

[Christ]

Hi I have a rock mt250 running a 169fmm motor and i have a pz30 carburator on it I wanted too know if that carb is ok for it if not what size carb and jets should it run
It isn't running properly

[NzBrakelathes]

Typically you need to correctly tune the carbs and PZ30 is fine for Chinese bikes.
Here’s a kit I’ve put together and suits a lot of bikes

https://rover.ebay.com/rover/0/0/0?m...2F303210680840

[Christ]

Ok the carb came with a 105 main jet and a 35 pilot jet

[Christ]

So the way I have it running is on the top setting on the adjustment needle and the air screw all the way closed is the only way it'll run

[JerryHawk250]

Pilot jet should be at least a 40. Start with the needle on the center slot If you have a 40 pilot handy then set the idle mixture a 1 1/2 turns out for starters. With the 35 pilot try rising the needle 1 notch from center and about 2 to 2 1/2 turns out. The 105 main should be good on a stock exhaust. 110 if you have a free flowing exhaust. These suggestions won't be exact but should be able to get it close enough to were you can get it running and tune from there.

[Christ]

So I tried all the notches on the adjustment needle and played with the air screw too and it only wants too run at the top notch with the air screw all the way in but once it goes under load it bogs down like it's flooded so it runs and idles but doesn't have the power I put a new cylinder and piston lapped the valves timing is good compression seems good I had someone else look at it and they say carb and so do I
I want to say it's getting too much gas

[JerryHawk250]

Check the float height and float valve to make sure it is seating. Definitely too much fuel on the idle circuit. Do you live in the US? I have a working PZ30 if you want it. Just pay for shipping.