Topic: vacuum frustration

[KeithB]

Can anyone point me to a detailed procedure on setting carbs on a '74 CB550 using vacuum gauges?
Thanks

[Deltarider]

Others will chime in no doubt.
Are you sure they're out of sync? Checking the ignition and sometimes a small adjustment of the timing can do miracles sometimes. My experience is that the carbs can stay synched for tens of thousands of kilometers.

[KeithB]

When I connect the vacuum gauges , they are not all reading the same.
Seems that would indicate an out of sync condition.
Also, I tore down and cleaned and re-built the carbs so unless I am a very lucky person, I suspect they are not synced.
So , yes, they are out of sync.

Now, any suggestions as to the actual question I need answered?

[MikeKato]

http://forums.sohc4.net/index.php?topic=83280.0


Bunch more threads on carb sync in the tech fourm
 http://forums.sohc4.net/index.php?board=132.0

  Feel free to bite my head off also if this isn't what you were looking for.

GL!
Mike

[bjbuchanan]

When I connect the vacuum gauges , they are not all reading the same.
Seems that would indicate an out of sync condition.
Also, I tore down and cleaned and re-built the carbs so unless I am a very lucky person, I suspect they are not synced.
So , yes, they are out of sync.

Now, any suggestions as to the actual question I need answered?

Only thing that would change your sync for your carbs would be screwing with the needle height, or just randomly playing with the adjuster. Most people think they need to sync for no good reason, it was just a suggestion.

Make a master carb, say #2, and obtain the highest vacuum reading until adjustment changes nothing for the reading. Now lock that locknut down and don't touch that carb again. Adjust the other 3 accordingly so that they all match up.

The focus is that you get the highest vacuum, which means the slide is lowest without being shut. That is the important part. The rest is just fiddling with knobs, probably got experience with that jk