a new valve will run about 100 bucks, worth it in my opinion.... just run amsoil interceptor oil....
heres a way to adjust them thanks to daman.
Ok,
set servo(idle down motor 900rpms and lower)and mark it
go back up to the servo and unloosen(turn in) all three cables
go back down to a valve and unbolt the housing(the two allen bolts on the outter housing)and pull
appart.
insert your two 2.5mm Allen wenches
go back up to the servo and GENTLY....tighen(turn out) the cable thus
taking out the slack till it just tuches the A/W,stop ypur done, but
be carefull over tighting will pull the servo pully off the mark,then you
would need to start over(settting the servo by hand alining the marks)
move to the next PV and repeat till all three are done."