Troy Bilt TB4 Blower valve adjustment

[MoreCowbellAz]

I know there's a similar question over in the motorcycle forum but maybe it's different for mowers, anyway I did the first valve adjustment on this blower (very long overdue), and I got to wondering if I should expect to see them tighten or loosen down the road. FWIW the intake was good, the exhaust was way loose. The mfr spec is .003"-.006", I didn't want to set it at either extreme so there would be room to roam with wear so that's where I got the question, I don't know which direction it will go. I set it at .004". As a comparison I know on my dirt bike they always tighten but that's due to the seats wearing and also that's a shim system with an overhead cam.

Anyway, runs awesome, and took almost no time.

 

[andyd]

Is the engine an OHV? Too loose is better than too tight. If exhaust valves get tight they will burn.

 

[MoreCowbellAz]

Yes OHV.

 

[spk2000]

Not always true as my motorcycle Ninja 250 has valves that tighten over time and it is DOHV. It depends how the motor is made and most do loosen over time.

 

[ironman_gq]

Depends on the engine, on the few ATV's I've worked on they go either way. Kawasaki engines tighten up and run like garbage if you don't regularly adjust the valves (100hrs or less). CanAm/BRP engines loosen up and start clacking but it takes hundreds of hours before they need to be adjusted (check at 100hrs, most don't get touched till 2-400hrs).