[TR] Z/S Carburetor Mixture Adjusting Screw

[Randall]

> I'm assuming this is just a little rust in the threads, and I 
> have filled the dashpot with PB Blaster to soak the screw.  
> Does this problem sound familiar?

Not a problem I've had, but seems likely.  Since the damper is supposed to
be isolated from the mixture screw threads by an O-ring, you might want to
squirt a little PBB in from below as well.  

IMO, it's also worth temporarily removing the indexing screw from the side
(which is supposed to keep the needle carrier from rotating in the piston
while you turn the adjusting screw); and seeing that the needle carrier
rotates.  That will also help work some PBB in to where the threads are.
Then when you reinsert the indexing screw, make sure it engages with the
slot in the carrier.  If it misses the slot, it can bind the carrier and
make adjustment impossible.

Also be sure you are "unscrewing" the adjustment screw.  If it's already
full rich, it won't turn any farther clockwise.  CCW is OK, though, at the
end the screw will just come out of the carrier.

The adjustment screw (and it's hex) are only brass, so don't apply too much
force.  A little heat might help, if nothing else does.

And IMO after all this, it's a good idea to replace the O-ring seal on the
adjustment screw.

Randall