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Top Norton Tech Talk Carburetor and Air Cleaner
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flying aceTue Dec-19-06 07:03 PM
Member since Jun 05th 2006
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"carb tuning what works?"


          

when tuning commando dual amals does the manual method result in smooth carbs and engine smoothness as much as a colortune or carbtune??? In fact can these 2 tools even be used on a commando?? edward

  

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dynodaveThu Dec-21-06 07:15 AM
Member since Dec 04th 2002
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#1. "RE: carb tuning what works?"
In response to Reply # 0
Thu Dec-21-06 07:16 AM by dynodave

          

It is likely that others have differing results based on their level of experience. I 'll give you my 2 cents worth.

colortune
This is only for idle tuning, the manufacturer states that it is not suitable for under power/load tuning since it can't handle the heat.

carb tune
If this is the venturi type flow/vacuum indicator??? like the unisyn?
I have one of these and the shaking motor hurts it's usefulness.

Individual mechanical guages are not consistant enough, I've had 2 sets and threw them both away.

Mercury carb sticks
This is what I use. (if I use anything)
They do not affect vacuum since the don't restrict flow.
You can symultaniously see both cylinders.
Just don't rev the bike and slap the throttle shut or you may suck mercury into the engine. And of course mercury is poison.

There are modern electronic sensor type of balance guages that seem to sork OK. Not sure of the price?

The biggest problem that I have discovered is that the fine or precise measurment of idle adjustment doen not translate to smooth running since few of us ride at an idle.

I know this is of little practical help but will offer it to illustrate the point.
Brake dynamometer
After all the fooling around with idle adjustment and then followed up with raised idle with the throttle twist....to attempt to balance the cylinder to cylinder pull...
The actual loading on the dyno (to make 8-12 hp) while adjusting the cable pull (with carb stix) will give a drivable smoothness that even very skilled tech will rarely be able to achieve.
This has been demonstrated at several "dynoday" open house at my place for the local norton club.

For curbside use I prefer mercury carb stix.
DAve

  

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flying aceThu Dec-21-06 04:36 PM
Member since Jun 05th 2006
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#2. "RE: carb tuning what works?"
In response to Reply # 1


          

Thanks for your input, Dyno Dave.

  

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