Hmmm .. ended up doing the same and then the manual shutoff stopped working but i didn't notice for awhile because the key shutoff still worked.

Didn't cross my mind that tightening up the the throttle linkages could have messed up the manual shutoff. Ended up with a huge increase in power and throttle response, the engine is also normal otherwise.

When I press the manual shutoff, there are results in that the engine starts shaking/missing.. but not enough for a shutdown.

EDIT- Actually, it was all awhile ago and just remember that I tried the manual shutoff awhile after the adjustments because the key shutoff started acting up/not working but then that problem (key shutoff) went away.

Given all that, I would think that if the linkage(s) get loose/out of adjustment, that could cause problems and would be easy enuff to check.

EDIT II - forgot that when the key shutoff acted up, changed out all the old, hard cracked rubber vac connectors and then the key shutoff worked again.