Re-jetting Webers

[rawKe20!]

ladies and gentlemen,

i was just wondering if anyone knoes of a good place to get my weber rejetted because weve messed around with it for hours and it just keeps running rich. I'm in adelaide and any help would be much apreciated, the sooner i get this done the sooner my car can be reunited with its siblings and i can come crusing.. peace .paul

[WinKE55]

So I take it you have been playing around with the mixture screw or the idle screw? I'm sure a few guys on here might be able to help you out without having to pay someone to do it for you.

[rawKe20!]

yeh not me personally but two of my mates are both qualified mechanics and weve taken the whole thing apart cleaned it all and re tuned but it just puts too much in . i doubt its the mixture screws. but thanks

[foc64]

My guess is you have a 32/36 DGAV weber from a Cortina or similar (2Ltr motor) so if you have this on a 1200cc engine it's no wonder it's running rich - no amount of idle mixture adjustment will change this, what you need to do is first establish what your current jetting is e.g emulsion tube, idle jets size, main jet size, air corrector size, pump jet size to do this you need to remove the top of the carb and unscrew the jets t ocheck the sizes (all the info will be stamped on the side of the jets).

 

Once you know this you will know what needs to be changed (smaller jets probably).

As a guide Ford used a 23/36 DFAV Carb on the 1300cc GT Escort (very similar Carb to the DGAV) jetting as follows:

 

Primary Emulsion Tube - F50 (Cortina - F6)

Secondary Emulsion Tube - F6 (Cortina - F6)

Primary Main Jet - 1.25 (Cortina - 1.40)

Secondary Main Jet - 1.30 (Cortina - 1.35)

Primary Air Corrector - 1.80 (Cortina - 1.70)

Secondary Air Corrector - 1.95 (Cortina - 0.70)

Primary Idle Jet - 0.55 (Cortina - 0.55)

Secondary Idle Jet - 0.50 (Cortina - 0.45)

 

Pump Jet - 0.55 (Cortina - 0.65)

Needle Valve - 2.00 (Cortina - 2.00)

 

As a starting point I would change the jetting to the same as the 1300cc Escort GT ones, from there you can fine tune and fine tune.

 

One last point, the Cortina Carb has slightly larger primary and secondary venturi's (26/27mm compared to the Escort - 23/24mm) but this shouldn't make a difference for your application.

 

good luck and remember to make notes of any changes you make, and most importantly only make ONE change at a time and then test before making the next one, might sound obvious but this is the biggest reason why people give up on carb jetting as they can't establish what was a good change or a bad one.

 

 

Chris

[rawKe20!]

thanks heaps man, answers like that make me glad to be a part of rollerclub , i think your right it was of of a 2lt datsun but its on a 1500 5k engine now but ill still take your advice and give it a look thank bud,, peace

[TOM]

Hi Paul is that the 5K motor you bought off Gavatron? If so I was the guy who was meant to buy it but couldn't in the end...

 

Anyway from memory that carby had just been tuned and jetted to suit that paricular motor - it was dynoed at 49 odd RWKW and when I drove it was running really well.

 

Perhaps your problem lies elsewhere... ie points, dwell, plugs, timing etc...

 

cheers,

tom

[1.6hydro]

Hi there if it running to rich best to down size your main jets.

That should clean it out up top, If it is still to rich at idle down size your idle jets.

As posted on here get a basic starting point from someone with the same engine and go

from there. Pump jets and Air correctors will help with fine tune the engine for great performance.

I have spent hours and hour on a dyno with all sorts of webers and very small adjustments to jets make a whole lot of difference. They are a very fun carby to play with once the basics are right.

[Gavatron]

If it's the carby that came with the motor you bought from me, it had just been rebuilt and jetted for that motor. Was running perfectly. What'd you do to it?

 

Auto Carburettor Services on Norfolk Rd at Marion were the guys that did it. Can't recommend them enough.

Edited March 16, 2008 by Gavatron

[Robert]

I reccomend Northeast Carby Services in Newton.

 

PM me if you want the number.