Motorcycle Repair: 1980 xr80 timing and head bolt torque specs, bolt torque specs, head bolt torque specs

Question
"Hello Mark, i am in the middle of rebuilding my 1980 honda xr8o. in the process of taking the head off, i removed the timing chain spocket that is connected to the cam shaft. before hand i marked both the sproket and the chain thinking i could just put it back together without any problems, i was wrong. the chain fell off of the bottom sprocket and the while the chain was off the engine was cranked over. so now the timing is totally off. i talked to a friend who said, with the piston at TDC, line up the mark on the bottom sprocket with the F mark on the left crank case.          he also said i should use modeling clay to make sure i am not 180 degrees out. to prevent bending       a push rod. could you please go into detail on how to set the timing( the procedure) and how to make sure i am not 180 degrees out. also i was wondering how many foot pounds you Recommend i torque the head bolts to.
My email address is bboarder98021@yahoo.com
thank you very much,
Brandon Jones  

Answer
Hi Brandon,

Before you proceed, get a copy of the service manual.

The service manual has information you need to know to complete the repairs properly. Mistakes are very expensive to correct.

Visit www.bikebandit.com to view parts microfiche and order service manuals. Also, check eBay and Barnes & Noble for manuals.

Modeling clay isn't needed to determine compression stroke on TDC. It's all explained in the service manual. It's very simple.

(Sorry, I don't have time to text lengthy procedures.)

Respectfully,
Mark Shively