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


TECH-0062


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 dont 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

Adjust your tappets to .003" intake and .005" exhaust

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 

Here is how to decide the piston alignment side 

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