Thread: 292 Questions
View Single Post
Old 06-25-2019, 09:43 PM   #69
RichardJ
Registered User
 
Join Date: Apr 2010
Location: So Cal
Posts: 1,419
Re: 292 Questions

>>Just checked the vacuum, there is none. Checked my gauge so I know its working.<<

You're using the wrong port. It is running, then you do have some manifold vacuum. Use the port you have that black plastic cap on, then toss that cap. You need a soft rubber cap for a good seal.

>>Idle adjustment is 1.5 turns out.<<

>>reset the mixture to 2 turns out ,<<

Idle mixture screw #turns out, isn't a setting. It's simply a preliminary starting point used to get the engine running. It is after that you make the mixture adjustment to what the engine wants.

On a 1bbl carb it doesn't matter where the mixture screw starts from as long as the engine starts. With a 2bbl or 4bbl or two single carbs, you want the mixture screws to be matched at least preliminarily. After that you try to keep them as balanced as best they will allow.

After the engine starts, hopefully the mixture screws are good enough to adjust the idle speed screw to 700 or below. All else being close, above 700 the throttle blade will be open far enough it will start pulling fuel from the transition slots, above the idle port in the bore. You can't adjust the idle mixture screw properly when rpm's are above idle speed and the transition slots are providing extra fuel.

The same goes for the timing. Most stock distributors start adding timing above the base timing in the 700-800 range. You want to set base timing without the mechanical advance adding any timing.
Where do you set the timing? Good question that you can answer after you drive it. Start with 10-12* and reset idle to 700 or below, then adjust the carb mixture.
Set timing with vacuum advance hose pinched closed or removed from dist and plugged.

>>There isn't much noticeable stutter until I basically have the screw out completely.<<

OK, start with that, although I would have expected the engine to die before that. Hope you don't have a vacuum leak.
With vacuum gauge and tach connected, start turning the mixture screw IN. Turn 1/2 turn at a time and let idle stabilize for a second each time. If idle goes above 700, reduce with speed screw. You're looking for the point where the tach shows a sudden and drastic drop in rpm. Take it back to the top of that last 1/2 turn drop off. Add an extra 1/2 turn CCW. It is in this area that you should also be seeing highest vacuum reading.
my 292 likes 650rpm. Below 600 I can see oil pressure drop slightly, so I stay above that.

Drive it. If it pings under load, you will need to retard the timing a couple degrees. If it doesn't ping, you can try and add a couple degrees to base. Trial and error. Always check engine rpm after timing change. I don't remember what distributor you have, If you have a points dist, make sure dwell is correct BEFORE setting timing. DON'T GUESS.

Last edited by RichardJ; 06-25-2019 at 09:50 PM.
RichardJ is offline   Reply With Quote