got miss-put bigger idle&main jets;won't cruise steadlyl

[vw moses]

got hpmx 40 carbs-went w/55 idle&130 mains--timed at 28deg.@3000--the motor pulls like never before,very powerful, But when i try to cruise,back-fire from carb. constant poping?only likes being floored--what gives??
_________________
Youtube@vw moses
73 thing-gone
66 beetle-gone
62 beetle-gone
57 beetle-gone
convertable-beetle-w/bugspray & screamer dist.(019) gone
"Where There's a Will There's a Way"
63 one of a kind beetle. 57 dash,double rear window--sweet!

[75smith]

running lean, either airleak(probably not if it idles well), main jet is too small or air corrector jet is to big

considering we don't know the engine size thats the best I can do, try jumping up a size on the main,

I'm assuming when you say cruise, your around 55-65mph, ~2750+ 250 rpms
_________________
My 1975 Beetle Build Updated 8-21-12

My engine build

[vw moses]

No, It wont go 30mph with out fighting,pop-pop-pop-only cooperates when i step harder on the gas-I got 130 main(HPMX40)came w/115-reccomend 125main according to hpmx recomendations? could the plugs be too hot or too cold? i chose the mediums from cb-It does run faster and never felt so much power!, But the low ends sucks--I must have drag strip equip. now--not street cruiser, very fustrating!
_________________
Youtube@vw moses
73 thing-gone
66 beetle-gone
62 beetle-gone
57 beetle-gone
convertable-beetle-w/bugspray & screamer dist.(019) gone
"Where There's a Will There's a Way"
63 one of a kind beetle. 57 dash,double rear window--sweet!

[Dougy Dee]

Clean out your idle jets.
Check for vacuum leaks at manifolds.

[MURZI]

Call me. You should have my number in a PM.
_________________
62 vert
2276
Tim’s welded heads
45 Dells
A1 sidewinder
Fk44 cam

[vw moses]

ok-went outside and started it up--idled fine--sprayed manifold base and carb. gasket w/b12 carb. cleaner- no change-idle jets cristal clean. what would make it backfire thru carbs? when i hold the gas steady, traveling??what could do it? totally stumped!HELP!
_________________
Youtube@vw moses
73 thing-gone
66 beetle-gone
62 beetle-gone
57 beetle-gone
convertable-beetle-w/bugspray & screamer dist.(019) gone
"Where There's a Will There's a Way"
63 one of a kind beetle. 57 dash,double rear window--sweet!

[stan_tichomirov]

Aren't those idles too big?

Stan
_________________
Aircooled.net
Jansen Enterprise
My 1835cc build
My budget 2276 build

[75smith]

[MURZI]

Did you sync the carbs with a snail?
Did you adjust your idle mixture screws?
How is the side to side play in the linkage ..sloppy, tight?
What is your initial timing?
Do you have 1 and 2 plug wires reversed?
What carb is popping back? Both?
_________________
62 vert
2276
Tim’s welded heads
45 Dells
A1 sidewinder
Fk44 cam

[vw moses]

No I didn't put the air gauge, But i got the throttle arms both about the same contact--screwed each idle screw in until drop in RPM,then backed out slowely until back-up to ideling-timing is 28deg.@3000-at idle 8-10bf tdc.Its got to be---jet still-too small to allow the motor to peform w/my larger-intake valve(40x35),big cam,exhaust-dist.---Should i ream the main jet up next size, Then test drive?
_________________
Youtube@vw moses
73 thing-gone
66 beetle-gone
62 beetle-gone
57 beetle-gone
convertable-beetle-w/bugspray & screamer dist.(019) gone
"Where There's a Will There's a Way"
63 one of a kind beetle. 57 dash,double rear window--sweet!

[stan_tichomirov]

32mm venturis? For 28mm venturis, your jets are way too big IMO.

Stan
_________________
Aircooled.net
Jansen Enterprise
My 1835cc build
My budget 2276 build

[vw moses]

Ouch! thats a thought-im under the impression--lean symptoms--but i never mention it appears the motor very hot; drove to gas station to top off w/gas (preium) The smell was hot -sorta like "too much burnt"also when i got home i looked at my valve vent tubes there was some smoke coming out not a lot but smoke,might be normal? So I don't know,i appreciate any&all the help!
_________________
Youtube@vw moses
73 thing-gone
66 beetle-gone
62 beetle-gone
57 beetle-gone
convertable-beetle-w/bugspray & screamer dist.(019) gone
"Where There's a Will There's a Way"
63 one of a kind beetle. 57 dash,double rear window--sweet!

[udidwht]

Did you clean the carbs thoroughly and make sure and check the float height-drop prior to install?
_________________
1972 Westy Hardtop/Type-4 2056cc
96mm Biral AA P/C's~7.8:1CR
Headflow Masters New AMC 42x36mm heads w/Porsche swivel adjusters
71mm Stroke
73 Web Cam w/Web solids
Dual 40mm IDF Webers - LM-2 - 47.5 idles/125 mains/190 air corr./F11 tubes/28mm Vents - Float height 10.45mm/Drop 32mm
Bosch SVDA w/Pertronix module (7.5 initial 28 total @ 3400rpm)
Bosch W8CC plugs
Pertronix Flamethrower 40K coil
S&S 4-1 w/Walker QP 17862
3 rib 002 Trans
185R14 Hankook tires

[vw moses]

i pulled the carbs off removed the idle jets sprayed carb. cleaner into hole then blew into with air-compressor&bubbles came out gasket top part took off cover and fliped over gasket tightened good-put back the idle&main jets that came with em. put back on started--poping all over again!changed plugs-1 wasblack,1 white,1shiny greay,1electrode almost touching center put in new plugs--still pops at idle!
_________________
Youtube@vw moses
73 thing-gone
66 beetle-gone
62 beetle-gone
57 beetle-gone
convertable-beetle-w/bugspray & screamer dist.(019) gone
"Where There's a Will There's a Way"
63 one of a kind beetle. 57 dash,double rear window--sweet!

[MURZI]

Loosen each idle jet one at a time until you hear the pop stop. That hole is your culprit.

Did you loosen the idle air bypass screws and then tighten them all the way up?? The little screws with jam nuts on them next to the idle mixture screws??
_________________
62 vert
2276
Tim’s welded heads
45 Dells
A1 sidewinder
Fk44 cam

[vw moses]

I did snug the idle jet screws-- should they be lightly seated? is there a blockage if too tight? but i'll try tomorrow-i,m blown away by this delema! i didn't touch the air screws(PROFESINAL TUNERS ONLY)factory setting.Its possiable i over tighened the seats, but i'll check it out. what do you make of the plug colors?
_________________
Youtube@vw moses
73 thing-gone
66 beetle-gone
62 beetle-gone
57 beetle-gone
convertable-beetle-w/bugspray & screamer dist.(019) gone
"Where There's a Will There's a Way"
63 one of a kind beetle. 57 dash,double rear window--sweet!

[75smith]

[MURZI]

The point is this. By gently unscrewing a idle jet holder you are taking the idle jet off seat allowing it to bypass and richen the circuit. By doing this one by one you will find the idle circuit that is plugged. The restriction could be in the jet or in the passage itself.
_________________
62 vert
2276
Tim’s welded heads
45 Dells
A1 sidewinder
Fk44 cam

[vw moses]

yes i set the floats according to weber carb. book (10mm up & 30mm down) thanks for the link; so far i'm concerned about idle jet because it coughs at Idle+reving,i'll study the procedure in carb. link. Thanks!
_________________
Youtube@vw moses
73 thing-gone
66 beetle-gone
62 beetle-gone
57 beetle-gone
convertable-beetle-w/bugspray & screamer dist.(019) gone
"Where There's a Will There's a Way"
63 one of a kind beetle. 57 dash,double rear window--sweet!

[vw moses]

OK-- When i had them apart i blasted the brass hole on top w/ idle jets removed with b-12 & air compressor.I think i'll put the 55idle jets back in because the stock idle jet is 52?? are you familar with the brass vent tube addition for the idle jet air feed tube?
_________________
Youtube@vw moses
73 thing-gone
66 beetle-gone
62 beetle-gone
57 beetle-gone
convertable-beetle-w/bugspray & screamer dist.(019) gone
"Where There's a Will There's a Way"
63 one of a kind beetle. 57 dash,double rear window--sweet!