[AT] IH 666 runs lean

[Greg Hass]

Here's my stab at the problem...

First, I am going to go under the assumption that the problem did not start 
until you replaced the fuel shutoff.  The 2400 loader tractor we had and 
the 656 Hydro had fuel adjustment screws on the end of the shutoff 
solenoid.  These screws literally adjusted the needle valve in the 
carburetor, so if the shutoff solenoid was replaced and it was this type, 
it may have to be readjusted.   We also have 3 IH 715 combines with gas 
engines and the fuel shutoff on them is simply a long, pointed rod with no 
particularly machined end.  These simply shut off the fuel and use a fixed 
jet for the high speed adjustment.  If it is this type, is it possible that 
the old one may have had a gasket between the shutoff and the carburetor 
body and the new one was installed without one, changing the internal 
clearances of the needle valve?  The only other thing I can say is that if 
you still have the old one, remove the spring that holds the needle up and 
try it for a short time and see if it solves the problem.  Good luck.

Greg Hass
Bad Axe, MI