Looking to get more power from a Youth size 110cc Atv - the stock carb is the PZ19, is the PZ20 a better carb for an upgrade or is it too much for the 110cc motor?

 

Won't make a blind bit of difference. 1mm in throat size is miniscule. In theory it allows a bit more mixture in at wide open throttle, but if the valves etc, don't allow that much extra in anyway, all it does is drop the vacuum slightly, weakening the mixture.

 

So I'll stick with the stock PZ19 then. Would a jetting change on it help?

Even though the 1mm difference is a small increase on the PZ20, thought maybe the larger jetting and tuning with the PZ20 would give more power to the 110cc motor.

 

Engines need the right mixture, bigger jets on an carb which is sending the right air/fuel ratio through already, will simply make the mixture too rich and drop power. If it is running weak now, bigger jets will increase power. An engine with a big bore kit, bigger valves, and/or high lift cam may produce more power from a bigger carb and different jets. By and large, a standard engine has the right carb and jets chosen by the manufacturer.