davefordham: howdy and welcome!!
My TTR125L manual identifies the following "regular inspection and adjustments" and maintenance intervals (assuming the initial 10 hour inspections were done, and with the usual caveats about conditions, how hard you ride, etc....some of these seem kind of far between, to me...):
Every Ride:
Front brake
Rear brake
Drive chain-check chain slack; make sure rear wheel is properly aligned
60 hours
Fuel Line
Spark Plug
Air Filter
Carburetor
Exhaust systems (check for leaks, retighten if necessary; replace gasket if necessary)
Oil
Clutch
Wheels: balance, runout, spoketightness/damage
Tires: tread depth, damage, air pressure
Wheel bearings
Swingarm- check for pivoting point play; lubricate w/molybdenum disuflide grease
Front Fork: operation and oil leakage
Rear shock assembly- operation and leakage
Chassis Fasteners- all nuts and bolts tight.
120 hours:
Valve clearances
Steering bearings
Sidestand
Spark arrestor
In the pre ride inspection it identifies:
Fuel; engine oil;
gear shifter and clutch;
throttle grip housing (freeplay/lubricate as necessary);
brakes, drivechain-slack, alignment, oil;
wheels- wear, tire pressure, spoke tightness, no excessive play; steering- no excessive play, smooth turning;
front and rear shock- no leaks, operate smoothly;
cables- smooth, not caught up in handlebars or forks; muffler- tight, no cracks; sprocket- nut not loose (I'd also check tooth wear);
bolts, nuts, lubrication; lead indicators: cdi magneto, cdi unit, and ignition coil are connected tightly.
You'd do really well to invest in the service manual. I ordered mine off the Yamaha site.