Mike---This is a check everyone should make if they can't get enough
richness adjustment out of their carb needles. As you noted, if the
jet/s is too high in its bushing, you may not be able to lift the needle
enough to compensate for it.
On my two ZS carbs, both jets measure .125 from the bridge down to the
top of the jet. (Not the bushing) This depth puts the needle adjustment
is about the center of its range.
If it's necessary to lower the jet, it can be done accurately by placing
a .125 thick piece of of steel stock (or cut a piece from a 1/8" Allen
wrench) and use this as a "stop" when doing the pressing.
Dick
Mike C. wrote:
I installed a Goodparts triple Z-S set-up. I was getting quite
frustrated as I could not get it to run right. The center carb (a used
unit that I totally rebuilt) ran extremely lean and at idle the 3 and 4
cylinders were not getting any fuel at all. I futzed with the float
level, installed a richer needle, all to no avail. Monday I took the top
off the carb to check for any blockage that I might have missed and was
going to swap springs with the rear carb to see if that might make a
difference. That's when I noticed that the jets were at different levels
in the carb bodies. The original carbs have the jets recessed 7/64 below
the bridge. The carb I bought used had the jet flush with the bridge.
With the help of a friend and his press we lowered the jet 7/64. Now the
performance is as I had hoped. With the PI cam it still has the idle
qualities of a washing machine full of boulders but it really rips once
you get it revved up. I am posting this in case there is some other poor
soul out there struggling with a similar dilemma. What a relief. Mike C
'71 TR6
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