I'm having a little problem with my 48 ida on my bridgeported 12a. If im just cruising it will kind of stutter a little bit and just wont stay constantly smooth. Do I just need to run bigger jets? i'm using the same idle jets that came in it (i bought it new). Thanks!

 

whats your cruising rpm? Could be right in the middle of changing from the low speed to high speed circuit in that range (not uncommon). You can usually combat that with air bleed tuning, but whats your jetting #'s in the carb? I'm not one of them, but many people here an tell you almost exactly what your jetting "should" be in that combination.

777 posts!

 

For example at 2500 it does it when in like 4th. but if im cruising down the highway in 5th at 2500 it feels fine because im on the pedal a bit more than i am in 4th cruising. I took out the jets right now.

Idle jets are 70/f10 with 120 air bleeds.
Mains are 135 with an f9 emulsion tube and i didnt see a number on the airs?

Those mains are waaaay to small for a bridgeport are they not? I should be using like a 200+ according to others. Could that cause my problem? Or do you think my idle is too lean, even though 70 seems more than enough.

I have a couple other questions too. What do the air bleed numbers mean? Like 120 air bleed, what does that 120 refer too? And the same for the F numbers. Like f10 idle jet? What does that mean?

 

Add a 3rd progression hole, start with 42s, 70 idle, 150 or less air, 210 main, 300 or gross jet and 0 by-pass jet. Modify your fuel bowl, ditch the fuel inlet screen and knock out the funnel going to the gross jet. Change your fuel pu.p to min 7psi with a good filter before the pump. Come back with the result as every engine has a different personality. 48 is good but 51.5 or larger is preferred.


Since bridge is known for lack of low-end, you can use 40s as a start but definitely you will need say 4.44 gears for better result...not too shaby for street and freeway use

 

it has a 3rd progression hole already. One question what is a gross jet and bypass jet? And im going to order a few the 40mm venturis and some jets pretty soon so we'll see how it works.

 

are you sure its not a 185 that didn't get stamped very hard?