stock carb tuning

[GuavaJam]

R u supposed to set needle first, or air fuel screw first? Does it matter? Thx

[bonesv]

On which carb/scooter? Is everything else stock?

[GuavaJam]

Sorry. 72cc DD50. Stock carb upjetted, stock airbox. When I roll on from about 1/4 throttle, I get an occasional bog. Always in the same spot. Dropped needle to second notch from top, adjusted a/f screw, but no luck.

[GuavaJam]

I can adjust the idle

[Eliterider]

.run ur bike till the motor is warmed up check ur plug to see if its running too lean or too rich.. If its too lean give it more fuel by turning the air screw outwards if its too rich go inwards. Then after you get that fine tuned u can set ur idle screw.. Remember air screw is really sensative so turn it a little at a time.also if u wanna run ur filter tune with it on...cuz tunning it with out a filter is different from having it on...as long as ur bike can hold an idle for u to tune your fine cuz u can set that after tuning...

[patthesoundguy]

.run ur bike till the motor is warmed up check ur plug to see if its running too lean or too rich.. If its too lean give it more fuel by turning the air screw outwards if its too rich go inwards. Then after you get that fine tuned u can set ur idle screw.. Remember air screw is really sensative so turn it a little at a time.also if u wanna run ur filter tune with it on...cuz tunning it with out a filter is different from having it on...as long as ur bike can hold an idle for u to tune your fine cuz u can set that after tuning...

You can't reall tell if the motor is running lean or rich by looking at the plug after running it normally or warming it up. If it's really really lean the plug could be very white, but cylinder damage would prob happen before you would have a chance to read the plug. To read a plug you have to install a new one after getting the motor up to temp and do a plug chop. And that will only tell you about wide open throttle. And you have the direction you turn the idle air screw backwards. It's an air metering screw so to richen the mixture you limit the amount of air flowing through the circuit by turning the screw in. What usually ends up happening with a stock carb when running a larger cylinder is the idle air screw ends up almost all of the way in if not all of the way in to get have almost no bogs in the low end.

[GuavaJam]

Thx I know how to adjust a/f mixture, but just wondering if u adjust needle or screw first.

[Eliterider]

Adjust ur air screw first

[Eliterider]

Pat u r rite when u talked about being too late..but it doesnt take that long to warm up a bike..checking the plug is a good start to tune a bike that way u prevent it from running too lean..its the basics of tunning a bike then eventually guys move on to just how it feel and how their bike sound...lol i did get my air screw backwards..

[GuavaJam]

rajah. will try and report back. thank u guys

[GuavaJam]

Changed to bigger pilot and main. Af screw 1 1/2 turns out, 2nd clip from top. Tried different positions and settings with no luck eliminating hesitation from quarter throttle roll on. Always in this spot only. Bike idles perfectly, accelerates nice. Also went back to new stock clutch and new rear trans. Thinking maybe needle size is wrong? Help! Thanks

[GuavaJam]

Btw, after adjusting af screw first, changing the clip position messed the af mixture. Bike would barely run