Topic: 1970 CB750 Carburetors

[dstirlin]

Hello, hoping for some help.
Have rebuilt carbs and set slides as recommended 1/16". When installed and run engine idles high at 2500-3000 rpm.
The only way I find to lower idle is to adjust each slide down individually.
The idle jet screws make no difference even when idle is down to 1000 rpm.
Any idea why this may happen?

Side note; I find recommendations that top nut on slides should be showing 1 or 2 threads. Mine go down much more to obtain suggested 1/16" slide clearance.

Thanks

[harisuluv]

Don't use the top adjusting nut to set the slide height.  Those nuts are to adjust cable slack.

The only adjustment to set the idle (slide height) is the 4 individual idle adjust screws (not to be confused with air screw).  And yes while the later models had linkage that raised and lowered them all at the same time, the K0 carbs have to all be adjusted individually.  Lower them as needed, you will probably need a vacuum sync.

[dstirlin]

Hi harisuluv,

Sorry, didn't mention that I have newer carbs (71-76) that has single linkage. 1 Cable.

In this case, is the idle set by the top slide adjustment? Seems only way to lower idle.

I synced carbs and still unable to get any adjustment from idle air screws.

Thanks for input.

Dave

[hondacaferacers]

Hey check out this website it might help you with your carburetor issue. http://www.dansmc.com/carb10.htm

[dusterdude]

The idle speed is set by the knurled screw that is between carb 1 and 2 and its a #$%* to get to

[evanphi]

The idle speed is set by the knurled screw that is between carb 1 and 2 and its a #$%* to get to

Especially if you have K1 carbs and a later model tank with the petcock on the same side!

I should get a second tank...