Idle Mixture Screw Adjusment

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Limey01
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Idle Mixture Screw Adjusment

Post by Limey01 »

Bought this at Walmart today for $13.97. Makes adjusting idle mixture screws a breeze.

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Re: Idle Mixture Screw Adjusment

Post by Larry Zimmer »

Neat! Thanks,
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Re: Idle Mixture Screw Adjusment

Post by tonybusa1300r »

What setting does everyone run there fuel/mixture screws at please. 😁

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Re: Idle Mixture Screw Adjusment

Post by jt »

Cannot see what it is, can you provide a direct link ?
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Re: Idle Mixture Screw Adjusment

Post by Larry Zimmer »

tonybusa1300r wrote: ↑
Thu Apr 30, 2020 1:15 pm
What setting does everyone run there fuel/mixture screws at please. 😁
You will have various responses. However, I'd suggest between 1 1/2 and 1 3/4. Don't go beyond 2.
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Re: Idle Mixture Screw Adjusment

Post by daves79x »

Over the years, various guys have tried (including me) settings from 2 - 3 turns out. I've long ago settled on two turns out max. I've had the opportunity to rebuild several sets of carbs over the years that I know for sure have never been touched from the factory. When I get such a set, a rarity these days, I always check how many turn open the pilot screws are. I've never found one over 1 1/2 turns open. Most are about 1 turn. This is how Honda would supposedly set them according to the procedure in the manual - using a high resolution tachometer and find the highest engine idle for each cylinder. This is why no two are exactly the same using Honda's procedure. I don't know anyone that actually does this. I bench sync the throttle bodies, set the mixture screws 2 turns out and gauge sync them if I have the whole bike here and can run it. Absolute perfection could be had using Honda's procedure, but you need a very precise tachometer.

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Re: Idle Mixture Screw Adjusment

Post by NobleHops »

daves79x wrote: ↑
Sat May 02, 2020 7:20 am
Over the years, various guys have tried (including me) settings from 2 - 3 turns out. I've long ago settled on two turns out max. I've had the opportunity to rebuild several sets of carbs over the years that I know for sure have never been touched from the factory. When I get such a set, a rarity these days, I always check how many turn open the pilot screws are. I've never found one over 1 1/2 turns open. Most are about 1 turn. This is how Honda would supposedly set them according to the procedure in the manual - using a high resolution tachometer and find the highest engine idle for each cylinder. This is why no two are exactly the same using Honda's procedure. I don't know anyone that actually does this. I bench sync the throttle bodies, set the mixture screws 2 turns out and gauge sync them if I have the whole bike here and can run it. Absolute perfection could be had using Honda's procedure, but you need a very precise tachometer.
We have been using a tool called a Gunson "Colortune", as a final step in tuning carburetors after we restore a bike after rebuilding carburetors, adjusting valves, etc. Opinions clearly vary on the merits of this tool, but I will say based upon our first-hand experience that the bikes start instantly, carburate crisply, and the plug insulators look light tan with little or no deposits on the electrodes. YMMV

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Re: Idle Mixture Screw Adjusment

Post by AshishNJ »

Bought what ? Link did not work for me either. Can you post Walmart link ?
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Re: Idle Mixture Screw Adjusment

Post by Larry Zimmer »

ALL: Apologies for the problem with the gallery photos. Unfortunately, the new software is having a hiccup recognizing the gallery. (Had to do it. Old software was being eliminated.) Meanwhile, if you can, when posting try to include photos in the post.
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Re: Idle Mixture Screw Adjusment

Post by budanddar »

Did not see a picture or part number for the mixture screw adjustment tool at Walmart.
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Re: Idle Mixture Screw Adjusment

Post by Irishman1 »

NobleHops wrote: ↑
Sun May 03, 2020 12:36 pm
daves79x wrote: ↑
Sat May 02, 2020 7:20 am
Over the years, various guys have tried (including me) settings from 2 - 3 turns out. I've long ago settled on two turns out max. I've had the opportunity to rebuild several sets of carbs over the years that I know for sure have never been touched from the factory. When I get such a set, a rarity these days, I always check how many turn open the pilot screws are. I've never found one over 1 1/2 turns open. Most are about 1 turn. This is how Honda would supposedly set them according to the procedure in the manual - using a high resolution tachometer and find the highest engine idle for each cylinder. This is why no two are exactly the same using Honda's procedure. I don't know anyone that actually does this. I bench sync the throttle bodies, set the mixture screws 2 turns out and gauge sync them if I have the whole bike here and can run it. Absolute perfection could be had using Honda's procedure, but you need a very precise tachometer.
We have been using a tool called a Gunson "Colortune", as a final step in tuning carburetors after we restore a bike after rebuilding carburetors, adjusting valves, etc. Opinions clearly vary on the merits of this tool, but I will say based upon our first-hand experience that the bikes start instantly, carburate crisply, and the plug insulators look light tan with little or no deposits on the electrodes. YMMV

N.
when using your color tune, how many turns out on the air/mix pilot screws do you find on average
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Re: Idle Mixture Screw Adjusment

Post by NobleHops »

JoeInTuc will have to answer that, but if I remember correctly, we end up around 2.
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Re: Idle Mixture Screw Adjusment

Post by NobleHops »

Joe confirms that we start at 2 turns before using the Colortune, generally dial them in +- 1/4 turn from there. Sometimes as much as 1/2 turn.
Nils Menten
Tucson, Arizona, USA '80 CBX, sort-of restored :-)

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