Topica Loopframe_Guzzi Archive


Subject: Re: On the subject of chokes....

Author: Patrick Hayes

Date: Jan 9, 2005, 11:19 PM

Post ID: 1718181056





bluezi-@att.net wrote:
 Can anybody tell me that if you switch from the cable choke to the choke
levers on the carb itself, if you can go half way, or can you set them
at half choke, or is it an all or nothing thing? There are times in a
good Pennsylvania chill that it would be nice to have a half choke
position for a mile or two, and with my cable choke, it's all or
nothing. Anyone out there have the levers on loop? Like em? Hate em?
What's your opinion?

Bill: You have to examine how the "chokes" or enricheners work on a
Guzzi. I speak about the square slide Dell'Orto carbs. You might
enjoy going to the factory site athttp://www.dellorto.it/linking to
the customer area and downloading the extensive manuals and diagrams of
internal function. The enrichening circuit is CLOSED by a spring loaded
plunger with a rubber disk seal on its bottom end. When you pull the
cable or lever you lift the plunger off its seat and liquid fuel flows
through the exposed port to dribble in and enrich the air/fuel ratio
(Hence the name enrichener instead of choke. A true CHOKE cuts air
supply to enrichen the ratio. These carbs do not effect air supply but
add extra fuel supply). Except for the first few thousandths of an
inch, the lifting of the plunger is an ON/OFF relationship. If you have
cable pulls, you can pull it less than 100%, but all of the service
function probably occurs in the first few percent of the lifting.
Typically, the on-carb levers raise and "overcenter" into a vertical
holding position. It is not possible to lift them part way unless you
hold them there by your fingers. Therefore, using cables or using
on-carb levers, just whack them all the way. It is really a Binary
ON/OFF function. Other carbs may vary.

Patrick Hayes
Fremont CA

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