timmya2

thank G for this forum..

ok.. i got a new webber installed


the guy who put it in.. done a great job putting it together.. he made custom plates, manifold and everything..to make it fit..


only problem he doesnt know how to TUNE it..

so he has to wait for his friend to come and tune it.. which may take a while..

my car is 12a stock/normal port used to have nikki changed to a webber.


main problems are

1. starting it - we have to put wd40 or carb cleaner on the two things on the carb u know those two big holes that come out on the webber.. yeh those things we have to spray it everytime to start it... but after its warm it starts ok.. and we have to give it gas and stuff.. basically a bitch to start when cold.

2. the thing runs ok above 1250 RPM, but below it.. it just keep dying everytime u push the pedal hard or even push it normally.. you have to litterally tap it very very slowly just to get pass 1250 RPM and then it runs fine after that. Like above 1250rpm.. its runs so beautifully, but below you have to very slowly push the gas until its above it, then u can press it as u normally would, even floor it.

3. it originally had size 200 jets in the webber.. so i replaced it with a pair of 145s.. it made a big difference.. he is thinking maybe even go lower.. wat do you guys thing the best jet size jets for a normal/stock port 12a mortor?

4. Idling - it doesnt idle nice and smooth anymore.. when i hear it. its not constant .. its like a fluctuating sound.. high then sumtimes low.. then back to high again.

5. and finally.. after i shut the car down.. it makes a BIG BANG NOISE! its like a friggen gunshot.. he said its running to rich.. too much fuel is stuck there .. so it burns off when u shut the car down.

please help me guys..

THANX HEAPS in advanced.. this forum has never let me down.. oh besides that once incident when.. bah nm


THANX HEAPS!!!

timmya2

oh i forgot to mention there is no choke on it now coz it wouldnt fit in with the new carb setup..

so does this mean its gonna be heaps harder to start in the cold now even after all the tuning is done?

timmya2

ok i just been searching in the forums..

it seems like u guys really really hate it when people spell it webber..

so ok just EXCUSE THE SPELLING PLEASE..

too late to edit it

bill Shurvinton

Umm. If its a weber IDA, it won't have a choke anyway.

To start cold, Pump 4 times on gas pedal then try.

The rest could be any number of things. You need to start from the beginning and work through the whole tune. I don't have any IDA numbers as a starting point though

timmya2

can anyone give me a good head start on tackling these problems.. wat to do first wat to change etc.

also forgot to mention it idles at 1.5k which after searching on the forum, found is way too high.

I thought this was normal.

what should it be idling at?

yeh as i said earlier.. the car runs fine.. its just basically starting it, and getting past that 1250rpm stage.

bill Shurvinton

The first level setup on a carb basically revolves around getting the butterflies in the right position so that you uncover the first progression drilling as soon as you open the throttle. (this is assuming you have sensible chokes and F3 or F11 emulsion tubes). If this butterfly positioning is wrong the car will run like crud until the main jets come in.

I'll add more notes later if noone chips in

Bill

Siraniko

iTrader: (13)

just my 2 cents
Hard starting: idle circuit is possibly clogged. Take everything out, spray with carb cleaner and blow it off with compressed air. I never had to pump my carbs more than twice prior to starting it. Turn the key on, let the bowl fill up for appx 10 seconds, then start.

Dying at high RPM: lack of gas. Either insufficient fuel pump or float level not set right.

SPECS that’s I used on stock 12-A: (my bros $200 SA with original paint,motor etc etc)
Venturies: 39mm
Idle: 75
Main: 200
Air: 175
E-tube: F11

timmya2

come on guys.. i need sum help here

i cant drive her properly and i havnt driven her in nearly 4 weeks! i cant wait any longer!!

lol i miss my rx7 so much

timmya2

i didnt say it dies at high RPMS..

i said below 1250rpm.. it tends to bog out and die if u press the pedal too much.. u litterally have to slowly tap it unti it gets past 1250, then its normal after that ..

i said it is idling way too high (1.5k rpm), it idles good though, is this normal rpm on a weber 48IDA ?

bill Shurvinton

Just a question. If it idles at 1500, how can it bog at 1250?

Have you checked the butterfly position yet? Without that you will always have a bog at low RPM due to the way the carb operates

timmya2

how do i check the buttefly position?

wat does it have to be positioned to?

bill Shurvinton

Find the progression covers. Take them off and see where the butterfly is. It should be just covering the first hole such that the smallest throttle movement uncovers it.

If this makes no sense you need to go and score a weber tuning guide.

timmya2

ok so what position does it have to be?.. ill try that too

right now my plans is to try a combination of different jets and emulsion tubes.. and see which one is the best.

im gonna try either these two combinations

F2 emulsion tubes
190-200 air jets
180-190 fuel jets
F10-65 idle jets

OR

F11 emulsion tubes
120 air jets
180-190 fuel jets

bill Shurvinton

If the progression is wrong you are never going to get the car running right.

PM me if you'd like me to send you a whole pile of notes and links on the setup.

Bill

RichRotorhead

I use F11 emulision tubes.

The down low hesitation could be due to a too big of a ventury. Try something around 38 or so.

Even when you get the jettin right, do not expect the car to fly flawlessly from a dead stop by smashing the throttle. Once you get used to the IDA you will realize that acceleration is more of a steady, smooth and progressive, procedure to get it to propel quickly without bogging.

-Rich

timmya2

thanx.. so with webers i cant just floor it without bigging out eh?

unlike the stock nikkis

RichRotorhead

Yes but it's not unique to just Webers, is every two barrel carburators, ie; Dellorto, Mikuni, 2 barrel holley's etc...

Once your jetts are in the right vincinity, an Air/Fuel ratio will help you fine tune it. Wideband preferably.

-Rich

RichRotorhead

You may find more documentation at www.mazspeed.com about this carb. Unfortunately they're on third site revision and a lot of old archived info has been lost, but I think you may get more active inputs from the members there, since it is a 1st. gen site only.

I take it you're new to carb tuning... if so there is one book I highly recomend (helped me tremendously) to help you understand how carbs work. Not sure on the title "tuning for power"? but the author is David Vizard.

Do a search in Amazon.com and it's bound to show up. Though not Weber specific, you'll gain a better understanding of what is going on with he car.

Good Luck!

-Rich

timmya2

well when starting we just hold the gas and when its warm it settles on 1,5k


mind u its not easy to start!

it tends to bog out and die below 1250rpm

fitzwarryne

In reality the 48 is on the large size for a stockport so you will have to scale down. You may end up with no more power than with a modded Nikki and a less streetable carb.

I suggest you take Bill's advice and read up the subject and as a starting point use the same set-up as Wackyracer which is a good middle of the road approach.

Any luck on your exhaust replacement problem? I heard Liverpool Exhausts do a great job with rotary specs.

timmya2

really?

dya have thier number?

timmya2

ok update..

we tried a friends combination suggestion..


F2 emulsion tubes
190-200 air jets
180-190 fuel jets
F10-65 idle jets
(but couldnt get 38mm venturis/choke, so we had to use a 40mm one)


AND IT WORKS!

it doesnt bog down anymore.. and drives soo nicely.. i think the venturi size were too big in the original setup.. ( is it 48mm? which is why they call it 48 IDA?)

all we need to do is rebuild it.. with the rebuild kit.. and it should be sweet..


also my friend told me in another forum




THAT wat was happening! it was so clogged up it wasnt squirting any fuel at all from accelerator pump jets.. so my friend had to clean all the crap out a bit so that it squirts.. its still not as strong though.. coz still crap build up in there... any suggestions on how to clean the accelerator pump jets properly so it squirts out strong when u open throttle..

thanx heaps guys for all your help


oh btw.. is it normal for webers to idle so high? 1.5k almost 2k when its warm..

sumtimes we adjust it down so it doenst idle so high when its warm

regards

REVHED

If it's setup correctly you should be able to get it to idle at about 1000rpm.