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NoOne65

Carb adjust

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Mikey    221

If you don't have a set of vacuum gauges (merc or otherwise), you could start with one screw and turn it down or up until things are smooth, then move on to the next and do the same until it's worse or smoother, and repeat until the end. Theoretically you should have just synced them. Much like tuning a stringed instrument based on previous adjustment.

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slowrideCX    385

The shop manal will explain how to do the carb synchronization.

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HANKSXXX    56

Set them all to 2 1/2 turns from out to start and adjust 1/4 turn out (for richer) or in (for leaner) as required.
The screws require a special tool which is D shaped and comes with some jet kits.

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NoOne65    19

Ok I have gotten my hands on shop manual but vacuum guages arent mentioned. I have done this before just been a long time so cant really rely on seat of the pants. Can it be done without a 50rpm increment Tach? they are set at 2 1\2 out from seated

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HANKSXXX    56

The gauges are used to synchronize the carbs, not adjust the fuel screws. Adjusting the fuel screws can be done with the idle drop method but I've always set them to the same number of turns out and called it good.

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Mikey    221

If I remember correctly, do the 2 1/2 turns. Then attach the vacuum line of each gauge to the respective inlet on the carb (see manual). It's a nipple that should be near the black large tube that is connecting to the engine from the carb. Then adjust the adjuster screw (see manual) until the line on the gauge reads a relative number to the rest. IE, if 3 are just about in sync, adjust one up or down to line up and do so on the next one that is out a bit until they all line up.

Short answer.

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HANKSXXX    56

Idle drop method is roughly this and presumes valves are set, carbs are synced, etc.

With the idle speed lowered to 950 or so, and a precision tach hooked up that reads small increments, start by adjusting the screws to highes most even idle and then lean out #1 fuel screw till the idle drops 50 RPM's, then richen it the minimum amount needed to get the 50 RPM's back..adjust each screw the same way. This is a precise, strenuous way to set the fuel screws which I'm not if the factory even uses as the spec in the shop manual refers to number of turns out.
My thought is it's an unnecessary complication resulting in little discernible difference.
Hank

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cecome    94
56 minutes ago, Dangerous Dave said:

Anybody know where to get a "D" shaped socket to fit these?

try factory pro

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superhawk996    797

People are fucking you by mixing up synchronization adjustment with air/fuel mixture adjustment.  The vacuum set is for sync, not for air/fuel, tho in good hands the vacuum readings could work.

 

Idle drop was mentioned so I'll tell you what I do.  After all other adjustments are good and the last thing is air/fuel you start with all carbs set to "X" turns out and a fully warmed motor.  You then screw the them in a 1/2 turn at a time 'till the idle drops, then back out a 1/4 or so and find the best spot for it and move to the next screw.  Once you've done them all go back through them and verify that each is at a setting that gives the highest idle or a hair leaner than highest idle if you want the cleanest burn.  There is absolutely no way to achieve a proper mix with "X" number of turns out that worked for someone else.  Altitude, mods, fuel quality, etc. will play in.  Anyone who tells you that "X" number of turns out gives the right mix is ignorant and you should purge that information from your brain.  If one setting worked there would be no adjustment ability, it would just be locked in.....as they are from the factory which works for a clean burn on a stock bike in most cases.

Edited by superhawk996
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superhawk996    797

And after re-thinking, my last statement implies that the factory just sets them to X turns out and AFAIK they don't.  They just lock people out from fucking with them by installing the tamper resistant plugs.  I believe it's only done because the EPA mandates that they not be adjustable.

 

Here's the procedure from the Honda manual.  It's pretty interesting and I assume if they went to these lengths it's because they found that it's the best way.  With cars the commonly accepted "right" way was using metered propane injection to measure the idle change.  I've always used my way from my previous post on every engine and haven't found a need to do differently even on emissions controlled & tested engines.

 

IMG_0393.thumb.jpg.49493728666add0b0473bbab39271f1a.jpg

 

IMG_0394.thumb.jpg.3e6e50c6ed4c36ad872a9d261e7832ef.jpg

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Thanks for the replies guys. I believe my bird needs both carb sync and idle mixture adjust. It smells pretty rich at idle with no choke. Idle is also a little erratic, and ditto for very light throttle away from a stop. I have a set of mercury sticks (I was a bike mechanic back in the '80s), but no "D" socket for the idle screws...didn't need one for Kawi. I'll check Factory Pro Tuning.

 

Tanks,

D Dave

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FiXXation    6

I've made a "D" socket for early 80's cars by using a 22 casing bent accordingly.  Don't know if that would fit your carb's screw or not.

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superhawk996    797

My first Bird was a '97 and when I bought it I thought the carbs were gonna need to be cleaned out, the idle acted exactly as if the idle jets were plugged up.  When I opened the airbox and looked into the carbs the butterflies were very obviously all over the place.  One was way open, another looked about normalish, two were pretty much closed so it was basically idling on 1 1/2 or 2 cylinders.  I'd love to meet the genius who did that to them, I can't imagine it just happened on its own.  As much as it bugged me it also helped me get a smokin deal on it ($1500) so I kinda thank him.  I first eye ball set them to see if that was gonna cure the idle and it seemed to do the trick.  I didn't have a manometer and wanted to get it rideable so I used a piece of wire as a feeler gauge to set them figuring it should get them close enough to start with.  It ran perfectly so I never bothered to get a manometer.  It would have been interesting to see how close to perfect the feeler gauge method got them, let me know if anyone's tried it.

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