Topic: Carb Vacuum Gauge Syncronizers

[34barab]

I'm debating whether or not to buy a set of carb syncro gauges for a pre-1976 CB750.  I've read various comments - some say waste of money as you only need to do it once every couple of years; others have bought them either because they get used more often.  I have two 750's, one which probably needs the carbs synced.  Buy or not buy?  If buy, recommendations for a good, easiest-to-use set. 

Thanks
John

[TwoTired]

You'll likely get the buy them responses from those who have and don't buy from those that haven't,  mostly to suport thrir own choices.

Some tools are job specific, but still neccessary to do a proper job.

Adjustable wrenches fit every nut and bolt,.  Still I wouldn't work on motorcylcles without a good socket set.

So it is with manometers.  You don't need them if your carbs are all set the same and your engine has all cylinders with the very same compression.  But, how do you know if you dont measure each cylinder under operating conditions?

Then there is the Honda Shop Manual, which outlines its routine use.

For me, it's essential to have proper tools for bike maintenance, as it is rare for me to find a shop that I trust to do the proper work on a machine older than the mechs.

Manometers are essential for me to get the smoothest idle out of multi-cylinder mult-carbed engines.

I suppose if you don't mind a rough idle, or a high idle speed, then you won't mind if your engine isn't running the way Honda wanted the engine checked and tuned regularly.  Then again you could be lucky enough to already have an engine with balanced carbs and 4 cylinders that have exactly the same volumetric efficiency.  Sometimes ignorance is bliss.

Cheers,

[MauiK3]

There is no way to truly set the engine up without a set of gauges. Bench synching works to get it running, gauges get them right under running conditions.
It's also gratifying to see/hear/feel the improvement as you do the adjusting.

[flybox1]

+1
Buy them.

[BenelliSEI]

Agreed....... NOTHING makes a multi carb motorcycle run like a final carb sync! After everything else is done (valve clearances, points, timing), it finishes the job. As a benefit, it usually takes most of the typical “rattle”  out of your cb750 at idle. After you’ve done a few it’s a twenty - thirty minute job and HUGELY satisfying!

[BomberMann650]

I've been pleasantly surprised with how often I use the carbtune pro vacuum meters.  There really is no substitute for a perfect synchronization. 

[bryanj]

If the points gap, timing, tappets, cam chain are all adjust EXACTLY RIGHT and the bench sync is done with a 1/16 or smaller drill shank and is exact 95+% of Hondas will be within tolerance on vacuum gauges, but NOT perfect, also you need to be doing a lot of servicing regularly to get the service items spot on.

[mrbreeze]

If you plan on owning a vehicle with multi carbs it makes all the sense in the world to have your own manometer. I would say 2 visits to a shop for a carb synch would pay for a good set. I used to have gauges and have heard bad things about mercury sticks. People make their own for cheap but I bought a Morgan carb tune and highly recommend it to others. I don't know what they go for these days but I paid right around $100 for mine around 10 years ago.

[hsas.69]

Buy them. Use them every tune-up, makes a world of difference in how smooth it will run and idle.

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[pjlogue]

I would get one and I would get a good one.  I used to have a set of cheap dial vacuum gages and suffered with them for many years.  I finally bough the carb tune ones and they were a good investment. 

Balancing the carbs is something I do if I change the carb slide settings or adjust the valve clearance.  It does make a world of difference in how the bike runs and idles when the carbs are balanced.

-P.

[przjohn]

I have no regrets when buying tools.

[Kelly E]

I have a Digisync 4 channel digital manometer with a built in tach. It works really well and the tach makes it easier. You can even get a 6 channel one if you have a Goldwing or a CBX.