Honda Shadow Spirit Choke

 The manual choke on my 2001 slides back in (that is open).
It fails to stay pulled out. What can I do to fix this?

 


I'm guessing that you have a 750 Shadow Spirit. Maybe you're not
operating the "choke" correctly.

Your Shadow Spirit doesn't have a "choke", as car mechanics would
understand a real choke, which has a flat plate that CLOSES and
restricts airflow into the carburetor.

Your motorcycle, and most Japanese motorcycles with diaphragm
carburetors, have a starting enrichener valve is pulled OPEN by the
choke cable and the open valve allows air to flow through a bypass
passage that goes around the closed throttle butterfly.

As air flows through the bypass it goes past a  small diameter passage
that goes straight to the float bowl. Gasoline is sucked out of the
float bowl like a child sucking milk through a straw.

That gasoline and air mixture may be as rich as 1 to 1, i.e., one part
of air to each part of gasoline. That's a very rich mixture, IF you
operate the starting enrichener correctly.

There isn't supposed to be any part "choke" operation. The knob is
supposed to be pulled all the way out, or left all the way in, nothing
in between.

You're not supposed to be twisting the throttle grip either. That just
defeats the operation of the starting enrichener by reducing vacuum
downstream of the throttle butterflies.

If your engine idles very fast when it's on the "choke" and you have
to keep fiddling with the knob, perhaps the idle mixture is too rich
because somebody has been tampering with the idle mixture screws and
has compensated by turning the idle speed knob up too high.

Now that I've explained how it all works, go to www.bikebandit.com and
look at the
CARBURETOR COMPONENTS schematic. Item # 11 is the "valve set starter".

You don't see much there, but each of the two little valves has a
spring on it that pushes it closed. If you look at the 1100 Shadow
Spirit CARBURETOR COMPONENTS you'll see the springs that push the
enrichener valves closed.

If you look at the other schematic (I think it's TURN SIGNAL CABLE)
that shows the choke cable (item # 5), you'll see the cable and the
knob.

The only mechanical thing that could cause the problem you describe is
the knob isn't holding the two little enrichener valves open, against
their own spring pressure trying to close them.

But, before you mess around changing the cable or the knob, just
remember, the knob has to be all the way OUT or all the way IN,
nothing in between.

 


 I'm not totally familiar with your particular bike, but on many there
is a plastic nut that you can tighten so the "choke" knob will stay
put. It's usually under a rubber boot, right about where the knob
connects to the cable.

 Many bikes have an enrichment knob, which does the same thing as a
choke, and despite what FB says can and are operated at partial
settings. I do it on my Suzuki all the time.

 On 30 Jan 2007 04:02:11 -0800Whilst not letting inanimate objects know


Ditto.Also on one of my old CXs the choke used to go back in and even
tightening the plastic/rubber nut didn't help so I just bent the choke
pull shaft as little(Gentley) so it made it stiff in the slide.

HTH :)



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 On Tue, 30 Jan 2007 16:35:30 +0000Whilst not letting inanimate objects


On the other one I can pull and twist for it to lock.



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