Gy6 50cc backfiring and bogging

[padly1995]

Hello,
i started with scooter i bought for cheap because it was working realy bad and it died in one week.
I putted in:
ONE YEAR OLD:
-clutch
-carburetor
-cdi
-coil
-spark plug cap
-spark cable

AND NEW:
-piston and cilynder
-stator and magneto
-oil

I also ajdusted the valves 100% perfectly, and i had to put the carb needle washer to the toppest position, after changing the piston and cilynder, otherwise it was bogging and backfiring like crazy at more than 1/4 throttle (thats realy strange because with old piston and cilynder it was working fine with washer on lowest position)!

Here is the problem: i cleaned the carb and it ran great for 3 days, than it started backfiring and losing power at acceleration, than i cleaned the carb again and it was good again for 3 days; 1 month it was like that.

I noticed that turning A/F screw does not giving any effect at all, i also removed auto choke needle, because it wasnt working at all.

Yesterday i took a little bit of silincer out and it was running alot beter, but than it started backfiring again; I cleaned the carb and nothing, than i changed the spark plug, it was a little better, but not much. Than i removed the plugin from line that goes from the airbox to carb and it was good again, but after 5 miles it started backfiring again. I cleaned the carb and air filter and it wasnt any better.

Thank you for anwsers, my english is not perfect, so i hope you understood it cheers!

[blueboy5000]

If the a/f screw does nothing, and you removed the enricher, I'd cut my loses and get a new carb.

If you did not plug the enricher hole, you've got a lean condition. Lean causes backfiring and popping.

You should make sure your intake has no cracks, and is tight to the cylinder, as well as the carb. If you are using an open element air-filter you need a #85 or larger jet, and even then, it is sometime necessary to "restict" the filter by covering part of the filter (with e-tape or something similar)

Sans air-filter, your bike will be much much too lean, so always use one.

This is all basic gy6 carb theory, yours will not take a/f adjustments, so save yourself the hassle and buy a new one.

[padly1995]

If the a/f screw does nothing, and you removed the enricher, I'd cut my loses and get a new carb.

If you did not plug the enricher hole, you've got a lean condition. Lean causes backfiring and popping.

You should make sure your intake has no cracks, and is tight to the cylinder, as well as the carb. If you are using an open element air-filter you need a #85 or larger jet, and even then, it is sometime necessary to "restict" the filter by covering part of the filter (with e-tape or something similar)

Sans air-filter, your bike will be much much too lean, so always use one.

This is all basic gy6 carb theory, yours will not take a/f adjustments, so save yourself the hassle and buy a new one.

Hy, thanks for your anwser :)

Hy, the intake is the part that connects the cilynder and carburetor toghether right? if thats so it has no cracks :)

I just removed the enrichers gold part and i putted the black enricher part back to its place so the hole is covered.

I have factory air filter. Im using factory 79 size jet right now, before yesterday i was using jet size 83 and it was like slower take off, but higher top speed and acceleration. Yesterday i repleaced back to 79 because it was backfiring little bit less.

BUT HERE IS AN UPDATE: Today i was driving for about 2 miles uphill and it just cut off and died. I waited for 10 minutes and it stared instantly, seens than scooter is running realy good -like never before.

Tomorow im going to buy new roller weights and belt :) thank you