> I turned the adjustment nut one flat up (leaner?) and
> found to my suprise that the nut was virtually at the end (fully closed) of
> it's travel.
A few people alluded to this, but I thought I'd mention it.
On the old "H" carbs, the jet bottom is a brass fork, that connects
to the choke linkage. On other carbs a fuel pipe goes here, but on
these carbs the fuel flows in elsewhere. Is this your carb?
Another "gimme" for identifying this carb type is that the float bowl
lids
are held on by one whitworth nut on top, instead of several slot screws
around
the edges.
Anyways, open the choke, and look between the adjusting nut
and the brass fork. You should see some of the jet in the space
now, it looks like a length of 1/4 inch brass rod.
Now release the clutch. You should NOT see any of this rod
any more, the fork should butt right up against the adjusting
nut.
If you see any rod here, likely the jet is binding.
Another test, remove the three screws and gently remove
the suction chamber. (the top bowl thingie with the dashpot).
Look into the hole, you should see the jet inside the jet
bearing. Pull the choke, and you should see the jet drop
down, release the choke and it should come up.
The jet SHOULD come up pretty close to level, within
1/8th inch of level or more, especially with the carb adjusting
nut all the way lean. This is actually what you are setting
when you adjust the nut, how high the jet comes in it's
sleeve.
Anyways, back to a likely problem, if the jet doesn't come
all the way up when the choke is off, again, the jet is binding.
Most of the time you can get the jet to unbind by just
centering it again, which is easy.
Put the dashpot back on, and screw the three screws on again,
we are done in there.
Above the jet adjusting nut is a spring, at the other end
of that is a slightly larger hex nut. Loosen that net a turn
or so, until it starts to feel loose. Also, raise the jet
adjusting nuts as high as they can go.
Reach underneath, and slide the jet up and down, use the
choke linkage as leverage if you need to. It should now
slide easily, all the way up to where no rod is visible between
the brass fork-thing and the adjusting nut.
If and when it slides easily, hold it there and tighten the
large hex nut you loosened a turn. Then see if it still rides
smoothly.
If it does, then you should be ok to tune up.
--
Trevor Boicey, P. Eng.
Ottawa, Canada, tboicey@brit.ca
ICQ #17432933 http://www.brit.ca/~tboicey/
"What a brave corporate logo!"
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