Topic: stupid question...where to hook up my carb sync tool

[hondacbrider]

Bike in question is my relatively new to me 1978 cb550k.

I saw this video:

and thought that would be easy enough...however, if you'll look at my attached picture, my intake manifolds don't have the vacuum ports. Carbs are 022A's....am I just not seeing the vacuum port on the carbs??

Thanks....

David.

[allhonda]

Just synced carbs on my 74 550. The screws to remove are nearest to the cylinder vs the carbs on the intake manifold. Is something backwards here?!?  Your pic does not show them?!?

[thehammer]

well in each of the cast aluminum intake tubes there is a 5mm plug that you take out and screw in the appropriate vacuum port fitting onto wich you slide the hose from the vacuum guage.

[allhonda]

I agree with the hammer.

[TwoTired]

You're screwed.
The 78's PD carbs have the vacuum port screws in the carbs.  The 022a, don't.  The 022As came on bikes with port screws in the intake manifold.

So, you have 78 manifolds (no vacuum ports screws) and 022s carbs, (no vacuum ports screws), for a total of no vacuum ports screws.

Whoever did your carb swap screwed up! 
If you want to use those carbs, you need to get 76 or earlier intake manifolds.
If you want to use those manifolds, you need to get a set of PD carbs.

Cheers,

[dave500]

the carbs must have been forced on,the centres have different spacings i thought?

[hondacbrider]

You're screwed.
The 78's PD carbs have the vacuum port screws in the carbs.  The 022a, don't.  The 022As came on bikes with port screws in the intake manifold.

So, you have 78 manifolds (no vacuum ports screws) and 022s carbs, (no vacuum ports screws), for a total of no vacuum ports screws.

Whoever did your carb swap screwed up! 
If you want to use those carbs, you need to get 76 or earlier intake manifolds.
If you want to use those manifolds, you need to get a set of PD carbs.

Cheers,

This is what was afraid of my friend...I will see if i can find one or the other as a replacement. Much appreciated.

I think some of the posters above didn't look at the picture I posted...

[thehammer]

huh . . .

[Duanob]

I don't see why you couldn't get a 5mm tap and drill the holes where you an get to them and buy 4 short 5mm philip screws. I'd try that and if it doesn't work you're back to the drawing board anyway and you'll have to buy new (used) intakes for the 74 - 76 550K with the air port..

[Accolay]

I don't see why you couldn't get a 5mm tap and drill the holes where you an get to them

Are the air ports strategically placed in the manifolds?

[TwoTired]

I don't see why you couldn't get a 5mm tap and drill the holes where you an get to them

Are the air ports strategically placed in the manifolds?

Well, technically yes.   The port monitors the vacuum in the runner between slide and intake valve.  Nearest the carb slide or fuel jet exit ports with probably give the most accurate balance.  But, I don't think supreme accuracy is really required.

Cheers,