First start on '73 R75/5, Idles too high.

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drcollie
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Joined: Thu Nov 26, 2015 10:28 pm

First start on '73 R75/5, Idles too high.

Post by drcollie »

Rebuilt both of the Bing 32mm Carbs - they were a mess. Went slow and took my time, replaced the diaphragms, all o-rings and gaskets, cleaned out the sludge from the bike sitting for almost 10 years. Started up tonight for the first time and immediately went to 4,200 rpm and would not idle down. Quick video:

https://youtu.be/p0e6rTVDTyY

Cables are slack, slides run free, good butterfly action. No idea why its hung up so high on startup. Any quick ideas what to look for?

I'm thrilled that it started. The rest will come with time and more work, I'm sure.

TIA
Duane
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Bamboo812
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Re: First start on '73 R75/5, Idles too high.

Post by Bamboo812 »

Have you checked the timing with a strobe? Could be too far advanced or a sticking advance unit.
Major Softie
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Re: First start on '73 R75/5, Idles too high.

Post by Major Softie »

For an idle that high, the first thing I'd do is pull off the intake tubes, look inside the carbs, and make sure the butterflies are actually closing all the way.
MS - out
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SteveD
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Re: First start on '73 R75/5, Idles too high.

Post by SteveD »

Have you backed off the throttle screws?
Cheers, Steve
Victoria, S.E.Oz.


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Duane Ausherman
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Re: First start on '73 R75/5, Idles too high.

Post by Duane Ausherman »

A simple quick test will show where the problem lies. A simple search with Google would have taken you to http://www.w6rec.com/duane/bmw/advance/index.htm where you would have a plan for diagnosing and fixing it.
Ask the Indians what happens when you don't control immigration.
Major Softie
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Re: First start on '73 R75/5, Idles too high.

Post by Major Softie »

Duane Ausherman wrote:A simple quick test will show where the problem lies. A simple search with Google would have taken you to http://www.w6rec.com/duane/bmw/advance/index.htm where you would have a plan for diagnosing and fixing it.
Hes BACK!
MS - out
Duane Ausherman
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Re: First start on '73 R75/5, Idles too high.

Post by Duane Ausherman »

While on the road, I often don't have the time, or Internet in order to post.
Ask the Indians what happens when you don't control immigration.
Rob
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Re: First start on '73 R75/5, Idles too high.

Post by Rob »

Duane Ausherman wrote:While on the road, I often don't have the time, or Internet in order to post.
Coffee at McDonalds.
Rob V
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