I think what happens here is the leak is a vacuum leak, so the volatile gasses
are sucked into the
intake and cause the RPMs to go up. Right?
You want to pay particular attention to the area around the shaft that goes
through the carb, this
is a traditional area of leaks.
Larry Hoy
>-----Original Message-----
>From: owner-mgs@autox.team.net [mailto:owner-mgs@autox.team.net]On
>Behalf Of Jon
>Sent: Friday, October 13, 2000 12:18 PM
>To: mgs@autox.team.net
>Subject: Re: High RPM
>
>
>Spray carby cleaner on the suspected leak and it will
>momentary seal the leak and RPM's change. You can do
>that on all the vac hoses and connections too. It
>works very well. I've also heard of, but never tried
>doing the same using propane (not lit) or O2 from your
>oxy/acety torch but I've never tried it. WD-40 works
>too if you don't mind oiling everything in sight.
>
>jon
>
>
>--- "Phillips, Frank" <fwp@ufl.edu> wrote:
>> List,
>>
>> Drove my B to work today and am still fighting a
>> high idle speed. I've run a
>> wire to the cockpit and now have the dwell/tach
>> meter plugged in so I can
>> see what is truly happening, the cars tach reads
>> high. My idle varies but is
>> mainly high. Idles around 1500-1600 RPM when it
>> should be 900 - 1000 (1968
>> MGB, AUD-265's). I feel there are air leaks in the
>> carb's. What is the best
>> (or any) way to check for leaks? Where else should
>> be checked? I rebuilt the
>> rest of the carbs about a month (6 weeks?) ago and
>> they seem to function
>> well. The car runs great as long as you don't intend
>> on stopping, high idle,
>> runs on... The running on is due to the high idle...
>>
>> On another note... I have fitted a mechanical oil
>> pressure gauge in-line
>> with the old electronic one still in place. Oil
>> pressure is great! The old
>> gauge tends to drop to zero at idle once the car
>> gets hot, new gauge read
>> about 20 - 25 psi. The old also read 5-15 below the
>> new. Cool!
>>
>> Frank Phillips
>> Campus Planning and Construction Management
>> Email: fwp@ufl.edu
>> http://plaza.ufl.edu/fwp/mgb.htm
>>
>>
>
>
>=====
>77 MGB "Christine" slowly, but surely healing
>
>58 Willys CJ-3B, Buick 231, T90, D18, D44, D25, 33X12.5 BFG's, custom exhaust
>by Jenson
>and Audiovox.
>
>She married me not for what I was, but for what she could make me...
>
>I like work; it fascinates me; I can sit and look at it for hours.
>
>__________________________________________________
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