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Re: More carb questions

To: "Jack Laird" <jlaird237@cox.net>
Subject: Re: More carb questions
From: "Jim Johnson" <bmwwxman@gmail.com>
Date: Fri, 9 Feb 2007 16:15:08 -0600
Jack,
Per our conversation last night I have no experience with the HS1
carbs, BUT....  My BMW motorcycles also use a constant velocity style
carb (made by BING). The symptoms you describe sound very much like a
common problem with the Bings...  Air leak!!!   I think you may be on
the right track. I would look for an air leak somewhere between the
carbs and combustion. That would explain a lean condition close to
idle that stops when the flow gets strong enough at higher rpm.
Cheers!!
Jim

On 2/9/07, Jack Laird <jlaird237@cox.net> wrote:
> Fuel leaks gone now but..........
>
> When I shoot a bit of carb cleaner at the throttle shaft rods, I get a quick
> 200 to 300 RPM increase from about 1300 which is as low as I can get things.
> Engine also smooths out immideately. As you have seen from previous posts I
> can not get idle below this range nor can I get the mixtures set. Always says
> it is too lean. ie when you raise a piston 1/32 inch it wants to quit. The
> engine is also very rough at lower speeds and will not jump to speed nor when
> at 2K or so drop back to idle quickly. All is well over 2K even on the road.
> Pulls good and smooth.
>
> Now for the questions.
>
> How much air leakage through the throttle bushing is acceptable??
>
> How snug should they be? If you can tell they are moveing with your had is
> that too much?
>
> Is there a way to measure this movement?
>
> Do you think I am on the right track?




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