Subject: Re: need help diagnosing problem- running rich - I think
Author: Patrick Hayes
Date: Mar 2, 2005, 9:14 AM
Post ID: 1718480204
brian c wrote:
| not check the seals- will do so tonight- but just out of curiousity- if the seals were bad, wouldn't that make the mixture more lean as more air |
I presume you have square slide DellOrto carbs. These are NOT chokes.
A horrible misnomer that we must continue to use.
A true CHOKE device regulates air flow. You choke it to restrict air
input and the vacuum sucks more fuel for a richer mixture ratio.
What we have on these carbs is an ENRICHENER. It regulates FUEL flow,
not air flow. On a normal running carb, the air intake, through a
venturi process, sucks in a proper ratio of fuel for that volume of air.
We need a richer mixture to start a cold bike. When you open the
ENRICHENER, you are opening a FUEL port and LOTS of LIQUID FUEL begins
pouring into the intake throat, thus a far richer mixture.
At the bottom of the brass choke plunger (there I go again) there is a
rubber disk which hits the bottom of the bore and seals this port. Look
at this disk carefully. I have seen torn ones and missing ones. Thus,
it is either ON or OFF. There is really no playing with the lever and
causing partial or feathered control of the enrichener circuit. Pull
the lever to open the flow, close the lever to stop the flow.
Patrick Hayes
Fremont CA