1980 xl125 has a very weak spark. Any way to test

4.9-5.3 oz per leg ATF so the Chiltons manual states. Equal amounts in both tubes.

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

Try this site here Drumhillcycle, then try Cycle Savage, or cyclesrus These three sites are used parts. Try this site for new, http://www.bikebandit.com They just may have some new old stock. Hope this helps Fix Ya up

yes u should have no problem

Your XL125 ignition system is designed to run off of battery power. You can remove all the lights but need to leave the battery, regulator, rectifier, and appropriate wiring in place. It is not designed to run like an ATC 110 (no battery) or a 2 stroke where you can run a single wire to a kill switch and down to the coil to power the spark plug. Put the harness, the regulator,the rectifier,and the battery back in and you should be in business.

manual will help

http://www.repairmanualclub.com/motomanuals/index.php

START WITH A NEW PLUG , OIL, AIR FILTER, THEN SET YOUR TIMING AT TDC ON THE FLY WHEEL THAT'S IT A FULL TUNE UP

yeah go on carlsalter.com there are loads of manuals on there for download for free