Holley jet ?

[dart star]

I have a 750 dP on my 360 we removed the choke flap
To get the extra power not overly experienced with carbs but
Learning so hears what I got the 360 has a large cam duration
And makes about 475hp the carb primary jet are#69 and have
A # 26 squirter the secondary jets are #80 with a#31:banghead: Squirter
So when I start the car I t runs rough till it heats up and it seems
To love the #80 jet when my foot is in it but it doesn't want to
Run when it's cold so is it the lack of choke flap or should I go bigger
Or smaller on.primary jet and or squirter. Thanks for replies

 

[abodyjoe]

all the choke is for it to richen the mixture when cold. taking out the flap is supposed to increase the air that gets in so in theory you would think it would use mor jet.

 

[abodyjoe]

here is where my 750 do was set for my 360. i had about 350hp at the wheels..

 

[73Scamp318]

Looking at Holley's numerical listing, it should probably have a 70 primary jets, 80 secondary jets, .028 primary squirter, .031 secondary squirter...sounds like it's pretty close to that. You can reference the chart with the number from the front of the choke horn for a baseline. You could also try abodyjoe's setup, though it's a different carb on a different car and may not work as well for you.

Removing the choke is most likely the cause of the cold running problems. If you mess with the jetting, idle mixture, and squirters to get it to run well cold, it probably won't run as good when warm. You can either live with the cold running problem or put the choke back on.

 

[ramcharger]

Don't put your foot into it on a cold engine, it's hard on the piston skirts. Yep, it'll run crappy without a choke when it's cold. Either wait until the engine hits about 160 before you drive or put the choke back on. Pulling the choke plate out may give you a few extra cfm, but it's really not worth it on a daily street driver.

You can richen it it up so it runs better cold, but then it'll run overly rich once it warms up.

 

[dart star]

Thanks for the replies guys they are just what
I needed to hear got 6inchs
Of snow in Ct boo now car is hibernating