[TR] SU H6 Carb Question

[Randall]

> The only way I can get the piston to 
> drop  with a click is to leave the assembly  untightened. 
> What should I do? 

What happens if you snug it all down, but pull the jet down by 1/2" or so?

If that produces a click, then your jet centering is off.  Otherwise,
something is binding.  

Have you checked that the piston moves absolutely freely in the dome with
the dome off the carb body?  The domes are thin and fragile, it doesn't take
much of a bump on the outside to make a dent inside.  And since the
clearance to the piston is so small, it only takes a tiny dent to make it
bind.

If the piston moves freely with the dome off the carb body, but binds when
you screw the dome down, then either the bottom of the dome or the surface
of the carb where it sits is not flat.

Note that pistons were originally matched to the domes; if you've swapped
pistons between domes it is possible that a big piston combined with a small
dome is binding.  There's a John Twist video somewhere about how to do the
"drop test" to check how well the piston matches the dome.

-- Randall