Captain Lou

I rebuilt My carburator last week, and after lots of tweaking and fussing around i have managed to get it together, installed and running smoothly,

I have no discernable vacuum leakes in the crab or between the baseplate/intake manifold that i can find.

THe choke responds correctly and it idles smoothly at 750-800 rpms

However, im down power.

On my stock car you could feel the secondaries open around 3500+ rpm dependingon how hard you're opening the throttle. Now they areopening either much later, or not completely.

the only way i can tell they are opening is the car still accelerates after i hit 4000 rpm, which it tended to flatten out before when my secondaries were totally nonfunctioning.

Is there anything i may have missed? someing often overlooked by first time carb rebuilders? Anything i should check?

Dan_s_young

iTrader: (1)

ever consider mechanical secondarys?

Captain Lou

I have considered mechanical secondaries, but given this was my first carb rebuild i wasn't overly keen in trying that mod, given it appears to be a rather finicky one to get "just right"

That and was concerned the gas mileage might make it brutal to run. Though it can't be any worse than before i rebuilt my carb


OKAY, so after monkeying about with it and cursing and pondering and driving around when i realised that the secondaries were not only opening late or not as much, but the car was really slow to spin up to an rpm where they would open.

It appears that something that holds the spring loaded arm that goes up to the throttlestop, and uh.. stops the throttle .. has broken and so its moving about, SO, it is hitting the stop inproperly and therefor im losing maybe 1/8" of movement? MEaning the throttle is only getting to 80-85% of WOT, which would make it display the slow to reach higher revs and the feeling of secondaries opening slow and not all the way?

If anyone knows what the plastic bit i broke looked like and can suggest something from teh hardwarestore i could put in its place so teh springloaded rod doesnt move side to side, thus hiting the stop properly ?

Captain Lou

fixed it!

bought some dense rubber washers from the plumbing section at home depot and cut me a new thingy to hold the rod inside one of the trottle retun springs in place, thus hitting the stop part without getting hung up.



teh secondaries are opening and have consistant power and acceleration as i step on the gas and wind the motor up. Now my problem is going by feel alone i can't tellif i ahve more power , less power or teh same amount as before i rebuilt the carb. The transition from primaries to secondaries opening is so smooth now, whereas before you felt a surge as they seemed to "jump" open.

Here's hoping theres more,

Captain Lou

I read that people remove the spring out of the secondary diaphragm to make them more responsive.

Does this actually work? i would guess removing it would make them open less precisely