tight valve adjustment

hello did the search I have a 143 F head did the valve adj 10,000 miles ago.what would make the valve adj go tight from .16 to a tight .10//i would think it would get loose but not tight runs great now.any thoughts//thanks

 

Mine tightens up too.. not sure if they all do or just the luck of the draw

 

hello how many miles do you go when the adj goes tight on you //thanks art

 

Valve seat and valve wear will tighten up the valves
Andrew

 

As the seats and valves wear the valve moves toward the rocker, reducing clearance. If the adjustment isn't made to compensate you'll eventually burn your exhaust valves.

 

thanks to all for the help i will keep a better eye on the adj///art