Topic: CB500 Carb Rebuild (1971 K0) - Initial Set up question - throttle slide height

[paulbaker1954]

Now have my carbs cleaned, re-olived, de gummed, polished etc and back together again. However I have one question.

I think I saw somewhere( but cant find it) a write up on setting the starting point for the throttle slide closed height. If you look at the pic then when closed the slides are a little off the bottom of the hole and wont go any lower even adjusting the balance screw heights.

Should I also be undoing the bolt and locknut on the main shaft and repositioning the shaft initially and then doing the fine adjustment with each adjuster.

[Deltarider]

Probably not but are p. 8-10 in the Honda Shop Manual CB500-550 of any help? http://www.honda4fun.com/pdf_man_officina/pdf_manuali/CB500-550/CB500-550-K_01.pdf

[harisuluv]

On the airbox side as pointed to in your picture, that's never going to be completely closed.  That's because there is a cut out in the slide.  The other side (engine side) will be closed (almost completely). 

[Trad]

I also had this question with my 627B cb500 carbs. I lowered the slides as fas as possible with the sync screws but they would not close 100 percent, even on the non-cut out side of the slide. It's close but not quite.

[harisuluv]

If they are closed 100% you will have no air or fuel...  you will need both.  even for just an idle.

[Deltarider]

A good starting point is to have the slides leaving a very little opening engineside, BTW that's the side I choose for bench syncing using a small allen key.

[paulbaker1954]

Thanks all I think I have this cracked now.

I have left a small opening on each throttle on the engine side and just set them all about the same "by eye", roughly 1/8" each.

Once I am running I will sync properly, adjust mixture and tickover etc