Idle Mixture Screw Adjusment

Post Reply
User avatar
Limey01
ICOA Member
ICOA Member
Posts: 32
Joined: Mon Nov 20, 2017 6:40 pm
Location: Eastanollee, GA, USA
Location: Eastanollee, GA, USA

Idle Mixture Screw Adjusment

Post by Limey01 »

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

7399
Better to remain silent and be thought a fool than to speak out and remove all doubt.

Larry Zimmer
ICOA Web Post/Pix/Video Archive Mgt
ICOA Web Post/Pix/Video Archive Mgt
Posts: 1788
Joined: Mon Dec 15, 2003 3:32 pm
Location: Brighton, MI
Location: Brighton, Mich
Contact:

Re: Idle Mixture Screw Adjusment

Post by Larry Zimmer »

Neat! Thanks,
Larry Zimmer
cbxlarry@sbcglobal.net

tonybusa1300r
New Member & Happy To Be Here
New Member & Happy To Be Here
Posts: 2
Joined: Thu Apr 30, 2020 3:15 am
Location: Newbury, UK
Location: Newbury, UK

Re: Idle Mixture Screw Adjusment

Post by tonybusa1300r »

What setting does everyone run there fuel/mixture screws at please. ๐Ÿ˜

User avatar
jt
ICOA Member
ICOA Member
Posts: 208
Joined: Tue Mar 04, 2003 10:59 pm
Location: League City, Tx
Location: League City, Texas, USA

Re: Idle Mixture Screw Adjusment

Post by jt »

Cannot see what it is, can you provide a direct link ?
JT In Texas

The biggest troublemaker you'll probably ever
have to deal with, watches you from
the mirror every mornin'.

Larry Zimmer
ICOA Web Post/Pix/Video Archive Mgt
ICOA Web Post/Pix/Video Archive Mgt
Posts: 1788
Joined: Mon Dec 15, 2003 3:32 pm
Location: Brighton, MI
Location: Brighton, Mich
Contact:

Re: Idle Mixture Screw Adjusment

Post by Larry Zimmer »

tonybusa1300r wrote: โ†‘
Thu Apr 30, 2020 1:15 pm
What setting does everyone run there fuel/mixture screws at please. ๐Ÿ˜
You will have various responses. However, I'd suggest between 1 1/2 and 1 3/4. Don't go beyond 2.
Larry Zimmer
cbxlarry@sbcglobal.net

daves79x
ICOA Technical Director
ICOA Technical Director
Posts: 4192
Joined: Sun Oct 01, 2006 8:05 am
Location: Knox, PA
Location: Knox, PA

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.

User avatar
NobleHops
ICOA Member
ICOA Member
Posts: 3256
Joined: Mon Jan 25, 2010 8:17 am
Location: Tucson, Arizona, USA
Location: Tucson, Arizona, USA

Re: Idle Mixture Screw Adjusment

Post by NobleHops »

daves79x wrote: โ†‘
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.
Nils Menten
Tucson, Arizona, USA '80 CBX, sort-of restored :-)

AshishNJ
Power Poster
Power Poster
Posts: 252
Joined: Mon Mar 25, 2019 10:26 am
Location: NJ USA
Location: NJ USA

Re: Idle Mixture Screw Adjusment

Post by AshishNJ »

Bought what ? Link did not work for me either. Can you post Walmart link ?

Larry Zimmer
ICOA Web Post/Pix/Video Archive Mgt
ICOA Web Post/Pix/Video Archive Mgt
Posts: 1788
Joined: Mon Dec 15, 2003 3:32 pm
Location: Brighton, MI
Location: Brighton, Mich
Contact:

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.
Larry Zimmer
cbxlarry@sbcglobal.net

Post Reply

Return to โ€œCARBS: Cleaning, Rebuilding, Swaps, Aftermarket, Tuning, Syncing, and Moreโ€