T H E O L D G R E E N B E E M E R
RIDING A 1974 BMW R90/6 FLAT TWIN
CHOKE, COLD STARTER
There is something funny in the communication between the cold starter device on the
bing CV carburettors and the actuation lever under the tank. Dropping the lever all
the way down opens the fuel enricher to maximum, but pulling the lever back up
till the '' notch '' halfway doens't make the engine run on half " Choke ". Why?
A short explanation is welcome and will make things clear. With a little work
done to it, you can make the lever behave more positive in its functioning.
Besides OFF the enricher or '' choke '' has three running positions, 1: a detectable
'' click '' , 2: something misty in between and 3: a full open position. Here I will
show you how to make the second middle position detectable as well
The enricher opened up reveals the regulator disk, three tiny holes are bored giving
three settings for extra fuel enrichment. That is if the actuation cable is mounted
correct: Hand lever fully up - lever on Enricher fully down to the stop, and v.v.
Small bore at the bottom of the circle is where the start fuel is being sucked up.
Superimposing reveals that the halfway '' click '' position is actually 1/3
enrichment and not '' halfway " as the hand lever makes you think.
Under the lever there is a hard metal ring with the one and only '' click '' position
This ring is hardened and too tough to drill, just grind in the second ( middle ) position
and you are done. From now on no more '' misty zone '' but positive actuation.
Continue to Carburettor Adjustment
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