Small Engines (Lawn Mowers, etc.): weed eater, mtd service, crank shaft

Question
How do I adjust overhead valve on a Troy Built weed eater model # TB525ES?

Answer
With the piston at top-dead-center (TDC) on the compression stroke, check both clearances before adjusting.  

I found two references for MTD/Troy-Bilt 4 cycle trimmers.  Both references require the intake valve clearance at .004 in.

However, the exhaust valve spec is different.

First reference says adjust both valves to .004 in.

The second reference for a model TB425CS states the following:

Valve clearance (intake)............003-.006 in.
Valve clearance (exhaust) ......... 013-.016 in.

From the MTD Service Manual:
1. To adjust the valves remove the valve cover.
2. Rotate the crank shaft to bring the piston to top dead center of the compression stroke (valves closed).
• Use the starter rope to turn the crank shaft.
• Use a probe in the spark plug hole to track the piston position.
3. The valve clearance for this engine is .003”- .006” (.08-.15 mm) for both valves.
4. Check the valve lash by placing a feeler gauge between the rocker and the valve stem. To adjust the valve loosen or tighten the fulcrum nut with a wrench until there is a slight drag on the feeler gauge when you pull it out.
5. Inspect the gasket that the valve cover sits on for damage. If it is damaged or compressed replace it.
6. Install the valve cover.

Did you check your owner's manual to see what it says?

Eric