Our 85 12a, all stock except for the carburetor off of a 91, runs rich when the choke is pulled out, so we found the lean and richness screw, and what we think is the idle screw, and adjusted it until it ran smooth with the choke out, but are afraid it might be too lean. We need help on how to make the leaness/richness right so we don't lose the engine. Thanks.

 

i'm assuming you meant a carb off an 81

if everything is stock, then the carb (granted it's in good condition) is perfectly setup. it's properly tuned from the factory. the idle mix screw is just that.... for the idle. where a lean/ rich situation could occur is where the float level is. if it's too low then you can create a lean situation, too high then the carb may cruise slightly richer. i've had the best luck running the level just a tad over the middle of the sight glass, where stock would be. (gotta be on level ground to make an accurate judgement).

does the car drive well?

 

What FBII said + non turbo rotaries (with stock carbs) are not prone to damage if they run to lean, the stock carb prevents them from geting enough air to do any real damage and are more likely to just be hard to start, and lean misfire under acceleration thus losing power, thats about it when using the stock carbs and exhaust. Now if you port, use headers, change timing, then the whole equation changes, but if you are 90% stock, and running lean, you are only hurting your power levels and drivability.

kenn

 

ok thanks and can some one tell me where the what is the bottom screw and what is the top screw and which way to turn them thanks it fills like it acc slower like it does not pull as hard .

 

Help

 

i need a pic of were the screws are and which do what and how to reset them please help just whet through town and at every stop light it would idle down and die

 

bump

 

Instead of bumping, try searching recent threads, next you'll want someone to turn the screwdriver for you. lol. Not trying to be a hardass but this issue has been addressed in the last week. Why anyone would set the carb with the choke pulled out is beyond me. The carb needs to be set while the engine is at operating temp and idling, 750rpm in neutral for a manual, same rpm, in drive, for an automatic tranny.

As a cautionary note, when you screw in the idle and air mix screws, to seat them before finding a baseline, be gentle or you could gall the seats and taper.

Btw, the carb is supposed to run rich with the choke out, that's it's purpose, to richen the mixture for cold starts. There are adjustments for this, but it sounds like something you should leave well enough alone.

 

no with the choke is out in cold starts it is so rich it slowly dies thats my problem thanks

 

YOur car should have an automatic choke release, star the car with the choke pulled out when car reaches normal op temp choke should release and go back in, if car goes dead then restart car and have someone keep the rpms up aound 750-900 until you can set the screws, the one near the fans is air/mix, the one nearest firewall is idle., Search the threads or get a manual shows, what to do.

 

ok