[BlackBetty]

of the day......350 mild cam aka rv cam, new carb, 550 holly.

A friend and I set this up a year ago. His electronic tools, my work it was right on the money. EXCEPT it was so rich that you couldn't stand around it before choking to death. Now that I have some time, I "ATTEMTED" to cut it back a little ...........OOPS yeah you guessed it. Got interrupted and FORGOT where I was....it starts fine but with 2300 rpms stumbles and pops.

Simple procedures with out timing and vacuum devices OH btw the power brakes were not hooked up yet nor the tranny vacuum
Insert Jack Bauer voice..."dammit"

 

[Bad66]

throw away the gadgets and let the engine tell you what it likes, adj. the timing and carb accordingly

 

[BlackBetty]

most common approach, from under the shade, says drop back to where it starts to stumble the forward to rich half a turn. what is the rpms I need to adjust the secondary??

 

[BlackBetty]

no carb guys today?

 

[mr. horsepower]

hey check the floats alot of people overlook that...
that might help your stumble. As for checking the fuel mixture on a holley take a buddy and have him watch the tach... start your engine and unplug all the vaccum lines off the carb and turn down the idle till it almost dies. then turn your air fuel screw on the drivers side in clock wise till the motor almost kills itself then turn it back out slowly a 1/4 turn at a time have buddy watch tach and turn till rpms jump. there will be a point when rpms stop climbing. stop and find the spot right where rpms are at the highest and give it an extra 1/8 turn. do the same on the pass side repeat twice for each screw. it also works well to use an old dwell meter gauge instead of a tach. you can hook it up right under the hood and watch the rpms yourself. Even a 100 or 50 rpm increase counts. good luck try it out.

 

[BlackBetty]

hey check the floats alot of people overlook that...
that might help your stumble. As for checking the fuel mixture on a holley take a buddy and have him watch the tach... start your engine and unplug all the vaccum lines off the carb and turn down the idle till it almost dies. then turn your air fuel screw on the drivers side in clock wise till the motor almost kills itself then turn it back out slowly a 1/4 turn at a time have buddy watch tach and turn till rpms jump. there will be a point when rpms stop climbing. stop and find the spot right where rpms are at the highest and give it an extra 1/8 turn. do the same on the pass side repeat twice for each screw. it also works well to use an old dwell meter gauge instead of a tach. you can hook it up right under the hood and watch the rpms yourself. Even a 100 or 50 rpm increase counts. good luck try it out.

fantastic, thanks!!!!! I am close to being on track then but will use your advice to tweak my efforts. Closest car friend I have is 100 miles away I live in OLD PEOPLE land. So, I'll try the dwell meter and give that a try. Makes sense.:beers:

 

[BlackBetty]

OH...one other thing. I've taken it back to the original settings and it is running better but back to rich again. This was basically 1.5 turns off of the closed positon on the front as well as the secondary. Getting unburnt fuel out of the exhaust just like before. If what your telling me I may be 1/2 turn rich??

 

[bb489]

Maybe a blown or sticking power valve?

 

[BlackBetty]

I hope not its a new carb. And I owe a correction....Eldebrock.
now that I have the a/f screws back to rich, the stumle has ceased but get a slight pop out of the exhaust....motor is smoother than before....so now fine tuning is in order.