Performance exhaust on stock gy6??

[tdawg92]

Hello everyone, I've been reading in the shadows for a while now and finally made an account.

So, I bought a 2010 roketa 50cc scoot a week ago bc my 2t adly noble 50cc broke down. So I needed new scoot to get to work until I fixed adly ( already fixed). So I bought the 4t with 1300 miles on it, came with Lo pro tires on 12" rims not 10" and a performance exhaust called "OUTS performance muffler" and says "DON'T TOUCH" under brand name. My question is, do 4th scoots come with these stock or did previous owner install it? I ask this bc my last 50cc gy6 I had was a lot faster(40-45mph no prob.) then this new one I have. I checked for restrictors..couldn't find any( didn't check cvt yet for one tho).. It will get to 20 mph no prob. But takes for ever to reach 35 and even longer to hit 40 mph and sometimes won't even reach 40.
I should also note it's has no balls what's so ever, when I'm at a stop at red light and it turns green, when I give it gas it Boggs and wants to die, If I give it more throttle it will catch its self and start accelerating, if I let off throttle when it does this it dies on mr in traffic.

So far all I have done to it:
Changes motor and gear oil with amsoil 10w-40 and amsoil 75-90
Changed plug with iridium one
Cleaned carb & air filter
Checked tire pressure

Still need to do:
Check compression
Adjust valves
Check how good spark is

So if my hypothesis is correct and the exhaust is not stock should I buy stock one from scrappy? Or would it b better to buy uni air filter and rejett the carb?? Also sometimes when I let off throttle it will let out a little " puh" backfire nothin to major tho.

Thank you everyone, all opinions count!
-Teryn

[MEAN_MOTOFINO]

Welcome!!!

[MEAN_MOTOFINO]

Check your plug you may be lean (white). You want it about tan.

Might need a larger main and may need to adjust the needle. Have you adjusted the a/f screw for highest idle?

[tdawg92]

No I have not yet, was gonna wait till my day off to do anything else, tuning the carb is something I wanna do next tho.. I haven't pulled plug since I put it in so I will pull that tomorrow morning and let u kno what I find. I do think its little lean like u said tho. Also I should mention that the whole vacuum system has been bypassed

[prodigit]

Check the variator, if the belt reaches the max. It does seem to take long time, so perhaps different rollers could do a difference.
Check the air intake, cvt and exhaust for spacers,, and perhaps change the CDI

[tdawg92]

Ok so I pulled the plug today, and MEAN MACHINE you were right... It was lean, really lean. So I put plug back in and looked at a/f screw and noticed it was only 1 1/2 turn out instead of factory 2 1/2 turns out.

So I set it back to factory tryed starting bike which wouldn't start unless I gave it gas. Got it started tryed tuning for highest idle but the idle wouldn't really change. I tryed to ride it and it keepers dying.

So I tuned carb back to where it was originally and looked for highest idle now, it's running little better now (better take off and acceleration) but,

When I walk on other side of scoot, I notice the sound I thought was the muffler wasn't coming from muffler..the sound is comin from area where header connects to exhaust port on motor. So I put my hand under it and can feel air being pushed out, also noticed the air comin out of muffler was weaker then my other 4t.

Could this be a potential exhaust gasket leak??

[rickmain]

Yes, it is an exhaust leak for sure.
Also, keep in mind the a/f screw only adjusts the mixture at idle and slightly above idle. A larger main jet is required for 3/4 to full throttle.

[tdawg92]

Yup sure was exhaust leak!! Bought new gasket and what do ya kno quiet as a mouse.. I think the outs muffler is just some brand of the canister type muffler.

Also today I took off carb to clean it and pilot jet was clogged bad...had to take wire through it. Put it back together, now I just need to put it back on and see how it runs! Can't wait. Thank for the help everyone!

[tdawg92]

Forgot to mention when I took the exhaust off the was never a gasket on it :/