The Stovebolt Site Forums The Shop Area Engine Shop can set the idle mixture with a vacuum gauge?

On a 216 with a rochester B carb what's the easiest way to set the idle mixture? I have black smoke comming out of my exhaust and spotting up the driveway as it sits so I think I need to set the idle mixture. Am I correct?

I don't think adjusting the idle mixture is going to solve the problem.

Is the choke all the way open?

Has that carb run?

LG

So more severe than idle mixture id check the choke too. Than possible rejet it, accordingly

To set a mixture screw, just turn it in till the engine begins to sputter, then slowly back it out. Or with the engine off, seat the needle then back it out 1 & 1/2 turns and then fine tune it with the engine running.

If you don't notice a rough running condition when you back it out 2 or 3 turns, go back in till it sputters again, then come out just to the point where it smooths out. Stay on the lean side and you should see some improvement.

Get it out on the highway to get some heat through the exhaust to clear it it out some. Recheck the mixture when the engine is hot.

PS, don't forget to check the choke and air filter for blockage.
Joe
Joe

There's some good information here http://www.thecarburetorshop.com/Troubleshooting.htm Read the section regarding "Bogs, Hessitations, stumbles" then scroll down to "Tri-power tuning tips" and about half way down is a paragraph on setting the idle. Hope this helps.

C