holley 750 stumble

[bowhay]

ok so when i goose on it in park it stubles for a slit second and then picks up
just cruzing its fine
but when i goose it while driving it stubles very badly especialy from a stop
what could this be?

[THERATTLER]

YOUR GOOSE IS LOOSE :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:

[CamBirdRacing]

You need bigger squirters and accel pump cams.

And WD40 for your goose. haha.

[dparker]

I'm waiting for Garrett to tell you what you need to do. lol.
X2 on the squirters, try turning the idle screws out a 1/2 turn, see if that helps.

[onedragracer]

YOUR GOOSE IS LOOSE :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:
Yep it's the loose goose happens all the time :D

[bowhay]

the squirters are 31s and james said those were fine
but i just rebuilt it and it didnt fix the problem
and its only doin it one the vacume secondaru kicks in
but the diaphram in it looked fine
so im kinda stumped

[cepx111]

If James said the 31's were fine then, by all means dont touch them.

It sounds like the secondaries are opening to quick.
They make a adjustable secondary kit so you can adjust on the fly or you can buy the indiviual springs to control the opening rate or speed that it opens the secondaries.

I wouldn't dare touch the squirters though, noway would I even think of trying some bigger ones first, uh uhh, that would be a total waste of time.

[Tod74]

If you have low compression /nearly stock motor the carb could be too big. My first motor I ever built was a .030 over 400 with stock pistons, 2.02 double hump heads and a ERSON HI-FLO 1 hydraulic cam ( .472 lift DUR @ 50 WAS ABOUT 230) I put a brand new 700 DP on it...every time I floored it it fell flat on it's face...ease into it it was fine. That carb had a 50cc pump on the rear.I tried bigger squirters and all that with no luck. I got a 650 DP that was box stock and nearly new...it had the small 30cc pump front and rear...That thing came to life in a big way! Instant throttle response. Car felt 3 times faster too.



edit: I should have read the whole thread beforte reply...didn't know it was a vacume secondary carb. :oops:

[jmarksdragster]

How much initial and total timing? Even with a near stock engine they can benefit with more initial timing and a fast curve.

[bowhay]

ok
so i went threw it again
and i figured the stuble was the vacume opening the flaps too early, so i disconnected the vacume secondary and made it a mechanical secondary

i was riight it took care of the stumble
but now there is another problem

it wont idle
it acts like all its doin is runnin of the gas that the squirter puts in when i pump the throtle before startin it
is this a float problem?

[Tod74]

If you make it a mechanical secondary I would think it would have made the problem worse....because you now are dumping the throttle blades open without the pump shot provided by the rear pump on a 4150 :?:

Make sure your idle mixture screws are adjusted properly.A turn and a half will be close but it's best to set them with a vacume gauge..adjust it to the point that gives the most vacume at idle.

[bowhay]

idk
but it fixed the origional problem

and i did that
i went threw the hole range on the mix screws with no change

i set the floats properly and it fixed the problem for about 5 minutes and then right back to how it was

so i thought is might be an air leak
and i sprayed carb cleaner all around the carb and there was no change in idle
im stumped

[Scooterz]

Bowhay:

Just an idea... but had similar symptoms once & it was the needle & seat which had a small particle stuck in it not allowing it to operate. Had the high idle, small hesitation, sounded very lean. Good Luck!