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Top Norton Tech Talk Carburetor and Air Cleaner
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JJerrySat Jun-18-05 09:19 PM

  
"RPM"


          

What rpm do you guys set your idle speed? I have been setting mine at about 800/850 but sometimes when it is warm after a ride it seems to pick up sometimes another 200. Istill haven't got rid of the bog after downshifting to 2nd at a corner when you want to lay on some throttle. Too lean?
Jerry

  

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RohanSun Jun-19-05 05:32 AM

  
#1. "RE: RPM"
In response to Reply # 0


          

What bike, what mileage, what carbies - and what ignition system ?

Some Commandos are a bit prone to having the advance/retard springs becoming tired over time and the unit sticking or not retarding at low speeds.

And the amal carbs wear in the slides and allow excess air past at idle, which makes for a fast less reliable idle. Worn valves/guides and/or pistons can also add to this effect....

opethiselps.

  

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JJerrySun Jun-19-05 07:57 PM

  
#2. "RE: RPM"
In response to Reply # 1


          

1974 850 Commando, Boyer ignition set at 27 BTDC. Carbs have only 2500 miles on resleeve. Sometimes idles at 600 until it warms up to 800/850 and then picks up more. It always increases when I put the lights on. Rcently it has been starting easier . It used to start sometimes on two kicks and next on twenty five . I've set ignitions on many bikes but this one continues to amuse me for three years now.

  

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RohanTue Jun-21-05 09:11 PM

  
#3. "RE: RPM"
In response to Reply # 2


          

The idle may be more reliable if you set the idle while the engine is well warmed up - ie hot. This may mean the cold idle is a bit slow, and rough, and will need either tickling or choking (or both) to start. My 73 850 (with points) was a certain 1st or 2nd kick starter with this setup. Your battery always needs to be good with a boyer - measured the standing volts ?

opethiselps.
Rohan.

  

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JJerryTue Jun-21-05 09:26 PM

  
#4. "RE: RPM"
In response to Reply # 3


          

Thanks for the reply. Battery is new. I have reviewed and gone over things time and again andstill puzzled. I am also 30 years exp with Triumph / only 3 with Norton. I am sure it will be sorted out. Thanks again , I do enjoy this site, Jerry

  

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