ok so i have a 2007 tomos lx a55 engine

First question i have is what is the carb that i have? is it the PHVA? and what mm? cause i am looking to do a little upgrade.


I just installed a brand new 65cc speed kit. i have a performance air filter, and a biturbo. Before i installed the kit i was doin around 40mph, now that i have installed the kit it seems that i am going a little slower. I have yet to upjet the carb, there is a 58 jet in currently. I know that i am supposed to up it to 74 or 76, but i want to know if the jet is what is keeping me from going as fast as i can.

also what size jet do i need? 6mm? again this is for the a55 engine.

all the info i could get from you guys would be great. Thank YOu



you should upjet! until then do not ride your bike! you will seize the motor.


u forgot 2 turn on warp speed

put fireworks on the back


clothespin a baseball card in your spokes 2 sound like a harly davidsen.


I'm 99% sure you've got a PHVA, but it should say on it somewhere. Take it off and look at it to be sure. I would also imagine that the size would be stamped on it somewhere. Again, take it off. Look at it. You could also try looking at the exploded diagrams at The only other stock Tomos carbs that I know of are the Encarwi and Dellorto SHA -- it should be pretty obvious from looking at the diagrams that you don't have an SHA or Encarwi if you've got a PHVA.

As Jesse said, STOP USING YOUR MOPED NOW UNTIL YOU UPJET PROPERLY. Do you know why upjetting is important? Your engine requires a specific mixture of fuel and air going into the engine to keep it lubed up and performing well. When you increase one variable, (like the air, which you increase when you add performance parts), you need to increase the other variable (like the fuel, which you increase by putting a larger jet in your carburetor). Without enough fuel in your ratio, your moped will (a) run like crap, and (b) probably seize.

A 70-whatever is probably a good place to start, but I'm assuming you got those numbers from one person -- there are a lot of factors that affect jetting, so what worked for that person might not work for you. Be prepared for your moped to still run like crap until you get it jetted right -- plug chops (in the wiki) help you do this. Yes, the PHVA's take the 6mm (info in the wiki on the Dellorto page.)

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