We got our kids a Speed Star 50cc quad for Christmas and I am looking to possibly upgrade the carb to something with some more control over the fuel. The current carb has a single fuel adjustment. Any idea how I'd go about finding carbs that will mate to the engine? Any identification numbers I can find don't pull up anything on Google which I'm assuming is pretty common with these Chinese quads. Any help on this is greatly appreciated. Here's a link to the model we purchased: https://www.redfoxpowersports.com/50...e-glove-goggle

 

Nearly all ATV carbs just have a single adjuster for low speed mixture adjustment, high speed mixture is either fixed or can be adjusted by altering the main jet needle in the throttle slide or dashpot. Further adjustment requires different jets. On quite a few, the low speed mixture screw is blanked off too so no adjustment is possible, there is a reason, you don't need to fiddle with it, unless extensive tuning has been carried out or you are at an unusual height above sea level.

 

So what is the process for adjusting the main jet? The quad does fine at low rpm's but it doesn't seem like it really wants to kick up in the higher rpm's. Are jets going to be specific to a certain carb or are they somewhat universal?

 

Carb makers sell various jets for each carb, small for weak, gradually getting bigger until it is running rich. With big name carb makers you can buy a set and work through them, until you find the perfect mixture for your machine. However I did mention some main jet needles can be moved up or down in the throttle slide, on modern stuff this is usually by taking the needle out and moving a circlip on it into a different groove in the needle.

 

I appreciate you taking the time to reply. I'll start fooling with the carb this weekend and see if I can figure out how to move the main jet. Can you reach down in there and just pull the jet out with a set of needle nose pliers of is there a retaining clip holding the jet in place from the top? I'm shocked there aren't any Youtube videos of this process anywhere around.

 

I should have clicked on that link you gave before, as that looks like the Mini Moto quad which has a two stroke brushcutter engine. generally regarded as throw away if anything goes wrong. Looks like it has a brushcutter/chainsaw carb too, which is totally different from normal quad carbs. Look up videos on chainsaw carb maintenance for instructions on repairs to them.