On Fri, 30 Apr 2010 15:22:03 -0500, The Black Knight wrote:

"Jules Richardson" wrote in message
...

[snip]

Is there a fuel shut-off solenoid inside the carb?

No... I'm not sure who made the carb, unless B+S rolled their own. It's a
pretty simple beast really.

It sounds like you are getting fuel to the carb, just not through the
carb.

Well, *something* is getting through because I can pull the carb off and
it's wet on the 'engine side' of the carb body. I wonder that's actually
a sign of the problem, though, and it's just not atomizing the fuel
properly and is getting neat gas pouring into the cylinder rather than a
nice mist (the presence of just enough vapor might explain the way it
tries to cough into life once sometimes, then promptly dies).

OTOH, maybe I'm clutching at straws ;-)

Oh, other possible symptom: the carb's getting a *lot* of gas; it drips
quite a lot from the intake side if I have the air filter assembly off
(the bolt that holds the filter on runs right through the carb body on
the intake). It's possible it's always been like that, and that's normal
behavior, but it surprised me there'd be that much gas "upstream" of the
choke plate.

Sticky float plunger

Possible, I suppose. I checked that the float isn't holed, and the
metering needle there looks good and seems to seat well (the carb sits
slightly lower than the tank, so if there were a float problem I think
I'd get gas pouring out everywhere even with the mower just sitting).

clogged passages

I can't completely rule that out, as there are a couple of passages I
can't really get to (access sealed at the factory), although I can blow
through them, so I know they're not completely blocked.

A partially shorn shaft key might goof up the timing a bit, but the
engine should still run if it fires at all. It's an all or nothing kind
of thing.

I might try to pull the flywheel (which times the ignition) just to check
that - it'd be a heck of a coinicidence if it just happened right at shut-
down last season, but stranger things have happened :-) I've certainly
had keys shear on smaller engines before.

Concentrate on the carb.

Yeah, I just pulled it again and double-checked what I could. I ended up
dumping a little neat brake cleaner into the inlet "upstream" of the
float and throttle, and the engine actually turned about four revs under
its own power before dying (it'd only do about 1 or 2 revs by itself on
gas). I can't decide if that's indicative of anything meaningful or
not :-)

cheers

Jules