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RUNNING CONDITION
Please got thru these steps:
Engine and Carb quick check list:
https://tboltusa.com/store/tech.php?pID=88/Engine+and+Carb+quick+check+list
To Check Valve lash (Tappet adjustment):
https://tboltusa.com/store/tech.php?pID=62/Top+End%2C+Valve+Clearance%2C+and+Timing
Jetting guide:
https://tboltusa.com/store/tech.php?pID=61/Simple+Guide+to+Jetting
Most of the time you can tune new bikes in with the needle and brass screw adjustments and not need to change jets
Tims TB20 jetting tech:
The 20mm ShengWay carb is relatively easy to tune right out of the box.
It comes with the #89 main and a #35 pilot jet
baseline setting:
I use the #90 or #92 main jet, the #38 or #40 pilot jet, set the jet
needle e-clip in the 3rd or 4th notch from the top, and the air screw at
1-1/2 to 1-3/4 turns OUT from seated. Make the necessary air screw
adjustments IN to richen it a 1/4-turn at a time and see what the bike
does. With some of the carbs, I've run it to within a 1/2-turn of being
all the way IN to get rid of 98% of the off-idle hesitation.
You might have to raise or lower the clip on the needle, depending upon
your altitude,
I'm at sea level.
Also be advised that the above settings are for use with an aftermarket
or bigger valved head, not the stock head.
You might want to try the stock carb jetting first, due to the smaller
stock head intake port.