The International CBX Owners Association

tonybusa1300r wrote: Thu Apr 30, 2020 1:15 pm What setting does everyone run there fuel/mixture screws at please.

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.

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.