How to set timing on a 1999 xr 70 honda dirtbike

SOURCE: How do you time a 2006 kxf450 dirtbike?

this is done via a bolt on the outside of the engine located on the head but i strongly urge you to go see a qualified motorcycle mechanic due to the fact that not doing this correctly will cause massive harm to the engine and if the chain falls off then you need to get the engine pulled apart and put back on which will cost you mega $$$$

SOURCE: honda xr 125 to set tappet clearances and adjust

timing chain should be auto adjust. set valve clearence to inlet 4 thou, exhaust 6 thou

SOURCE: Just rebuilding 2001 honda xr 80 and need to know

Valve timing is done with the piston at Top Dead Center. The cam lobes should be pointing downward. There will be a mark or marks on the cam gear for alignment of the gear. If only one mark, it should be at the top and inline with the centerline of the crankshaft. If two marks, they sholud be parallel with the surface of the cylinder. Any slack in the timing chain should be at the carb side. When the cam gear is in the proper position, rotate the cam slightly to line up the screw holes for mounting. After mounting, remove the spark plug and turn the engine over by hand to be sure the setting is correct. If the crankshaft locks up it is because the piston is hitting a valve. Re-do the cam timing. Please rate my answer. Thanks.

SOURCE: witch mark do i use the f or the t mark to put a 81 honda xl125 dirtbike n time

The T mark shows TDC usually used to set timing for camshaft etc...
The F mark shows the firing point and is used to set ignition timing...
Here is a link to download a free service manual...
http://www.manualedereparatie.info/manuale/honda/Honda_XL_XR_TLR_125_200_200_R_1979_1987_Manual_de_reparatie_www.manualedereparatie.info.zip