Top End, Valve Clearance, and Timing
TBolt USA Tech Database!

To get everything together properly on your Pitbike 4 stroke single top end heres a few tips

Some Big bore kits have thinner head and base gaskets than stock
With these do not use the stock "O" rings
You may want to use a thin layer of Yamaha bond or honda4 semi drying adhesive

Set you Flywheel to "T" mark (top dead center)
then align you top cam sprocket mark to 9 o clock

Valve Lash - Valve tappet adjustment
KLX110
HONDA 50-70
China 50-190
Daytona 190 
Adjust your tappets to .003" intake and .003" exhaust 

TBPARTS NOTE:
Valve Lash Settings for All TBparts Race Heads & Camshafts:
Intake 0.003" & Exhaust 0.003”  
Note - This gap between the valve tip and rocker tip is necessary, it closes when the bike gets hot.

In all applications regarding the use of TBparts
Install the camshaft with the lobes down or toward the piston.
This first step combined with aligning the camshaft timing marks and crankshaft timing marks will ensure your engine is timed properly.


Note:
2 bolt cam mounting bolt holes are offset drilled and only go on one way
so it cant be 180 degrees out

Torque the head to 110" lbs, run for one heat cycle then re-torque
110in/lbs is for the 50-110cc round cam cover type and Honda 50/70 6mm studs

Torque the head to 140" lbs, run for one heat cycle then re-torque
140in/lbs is for the 125-150cc round cam cover type and Honda TRX90 7mm studs

KLX110 and KLX head type motors ZS155, 155HO and YX 150/160
16ft/lbs ,run for one heat cycle then re-torque 8mm studs

Heres is a YouTube of a guy setting his valves 

https://www.youtube.com/watch?v=HppcqVpnaFw 

Special Note about TBparts KLX114 143cc kit piston TBW0377
TBparts 143cc 60mm piston part number TBW0377 that is sold in all of the 143cc bore kits has the IN marked on the smaller valve relief and it is correct.
The Exhaust relief is larger because our piston was made to work with several different cylinder heads.

?Here is how to decide the piston alignment side: