Agility 50 big bore 70cc

[TuttoCambia]

It happens at about half throttle..its not that bad during the day but at night when its colder it happens more often and again thats with a 85 main jet.

[Shaka]

Does the "cut out"  stop if you throttle past that point?  You may want to try lowering the needle and do a plug chop.  If it runs ok at full throttle the jet is probably right.  If you can't get past the 1/2 throttle cut out, then you probably need to address the size of the main jet.

[Kenho21]

What is plug chopping?

[Shaka]

You put in a brand new spark plug and fun the bike at only the throttle position you want to check.  Then you kill the engine while still holding this throttle position until it fully dies.  Then you pull the plug and examine it.  This is your "window"  into what the engine is doing at that particular throttle position.  You only need to run the bike for about 1 mile.  You are looking for a nice caramel color around the base of the center electrode, down inside.  It's hard to see down in there, that's why they call it "chopping" because to get a real good look you have to cut the plug.  Do a google search of plug chop and you will find lots of information.  It's not hard and it is the only real way to tell how the motor is really running.  You don't really have to chop the plugs either, you just have to be able to see way down in there.

[zombie]

I like the idea of the air filter, and don't forget you also have the jet needle to fine tune with. It's easier to see results here, because of the access. Get it as close as poss. w/ the jet, and then see where the needle takes you. Everything must work together to get a smooth response across the board.

[TuttoCambia]

what is the jet needle..is that the same thing as the mix screw? and which one is the mix screw or jet needle. the only one I see to adjust is the idle screw.

[Shaka]

The jet needle is inside the carb.  It sticks out of the bottom of the slide.  You access it by unscrewing the top of the carb where the throttle cable enters.  The idle screw is usually the screw in the center.  It sticks in to where the slide is and changes the idle by either raising or lowering the starting point of the slide.  The mix screw is usually just forward of the idle and a little lower.  If you pull the screws all the way out, the tip of the idle screw is larger than the mix also.

[thatsdax]

This is what I know.. I have done 6 scooters all of them GY6 4 strokes..  I have put on the big bore kits. I can tell you the upgrade to power is amazing.. Install can take an hour or 2 on the first one. The second only takes an hour at the most. Again.. These have all bee GY6 139qmb engines.. Here in Colorado, you must be 16 with a valid drivers license in order to drive a 49cc scooter. You must also have the Low power sticker and valid insurance. You do not need to have a motor cycle endorsement .  Once you Get the VIN, proof of insurance , then you can get the low power sticker from Colo Dept of Revenue, and then you are legal provided you are 16 with a valid drivers license.  Now.. About the Power up kit.. Who is going to know?  And how would they know? By adding a power up kit to your 4 stroke, you will be able to do 45mph on the flats and up hills.. You will no longer be hugging the white line at 30mph or 35 on a good day..  The power up kits will only help everyone !!  Cars will not be angry with you.. Besides.. The power up kits for the 4 strokes will allow the 4 strokes to go like the stock 2 strokes .. Maybe a little more.. Maybe.. But.. REally. About the same.. The power up kits really are needed for the 4 strokes as they really are slow out of the box.. And they, or they have been easy to do and worth every penny ..
 
   Now.. With that.. I must say that I have never done a Kymco 4 stroke.. But I am going to.. I just bought a very nice Kymco Agility 50T 4S with 800 miles. It is a stock all the way scooter.. Slow for sure.. Runs ok.. But does not make the power.. It is a 50 4 stroke.. So.. I have been doing a search for a Power up kit for the Kymco. From what I can tell. It is the same kit for the GY6 139qmb as for the Kymco. And I still have a spare power up kit for the 139qmb .. Yes !!  So.. Keep Posted. I will let you all know how this power up Kit goes for this Kymco 4 stroke. 

      As for all the other power up kits I have installed.. I can tell you.. it is worth it big time !!   I have done 4 of my own scooters, and 1 customer scooter.. And all have been fantastic !!  The only thing I install is the new cylinder , piston, and ring sets. That is all.. Keep everything else the same.. What you want to do is this. Make sure your scooter is running correctly before you attempt to install any big bore/power up kit. If you have a good running scooter, then once you are done with the power up kit, you will be amazed.. No Carb Change is needed, no change in jetting is needed.. Simply install the base Gasket, new cylinder with piston and rings, and new Crush Head Gasket.. That is all !!  And once you are done, you too will be amazed. You will  have a blast !!   I will do a video on this Kymco Scooter using the GY6 139QMB big bore kit.. So.. Keep in touch !!  And.. Enjoy the ride !!

[streido]

Interesting you say no change in jetting was needed Dax cos as far as i was aware everyone here who did it had to upjet on a BBK?

[MotoRandy123]

   Seems funny no jetting is needed but maybe the airflow through the stock airbox and
exhaust limits the power gain so you don't need much extra fuel. So you probably get 1
hp and with a few tweaks to intake and exhaust you could get 2 hp....

[wordslinger]

you will be able to do 45mph on the flats and up hills..


..my 08 a50 did that without kit...hmmm...

[MotoRandy123]

Maybe an aftermarket 70cc makes less power than the stock 50cc?

I know some Chinese scoots make a lot less power than the name brands.
From the EPA a Qlink 150 makes 6.5 kw and the Kymco movie 150 makes 9.9 kw.

[blue]

you will be able to do 45mph on the flats and up hills..


..my 08 a50 did that without kit...hmmm...

x 2 mine does 45 or better with a 20 mm carb and a 85 jet. and open air box.

[wordslinger]

as far as i was aware everyone here who did it had to upjet on a BBK


...oh, hell...i know several ppl that didnt...aint running now....

[blue]

Only so much can be done befor the bang hits you. its better off just geting a bigger scoot.
everyone that does the bbk is just another way of geting buy so you dont have to get a cycle endorsement.
and dont have to worry about insurance.................. thats why we drive 50.s