tuning a 32/36 webber????

[WAY2LOWatwork]

how do u tune thes carbies? cause no matter what i do i can never get this carby to work right!!!!
the carb is off a mk2 escort 2ltr, has been jetted down (135, 140 jets from memory) the jets were 175 and 180.
where do i start?
the engine its on has a cam, carb, extractors and exhaust, but otherwise stock.
next question.... 2 barrel carbies are suposed to spray fuel down both throats, correct? cause this 1 only sprays down the primary. i pulled the carby apart and looked at the jet thingy that sits in the midle of the carb and sprays fuel, the primary side has a hole in it to let fuel through but the secondary side has no hole at all, its not blocked, it has no hole, is this how they are supposed to be? or should i just buy a new carb?
cheers
justin

[GasGem]

Progressive Carbi!!!!

2 throats, but 1 at a time so fuel only needs to be sprayed down 1 throat.

have alook at Ben Wright's tuning gide under the links page of this site,

Start with the idle circuit and work your way up,

cheers
Eggy

[WAY2LOWatwork]

cheers

[WAY2LOWatwork]

thats all helpfull and ill rebuild it, but i still need to tune the sucker!

[GasGem]

OK,
Quick rough guide to tuning,

set your timing correctly
Primary side of weber. ( butterfly that opend first)

1, get the idle right.,vac gauge on manifold beather, the higher the reading that can be obtained while the engine runs at it best, is the most correct idle mixture.

open the throttle just a little, do the rev's pick up cleanly and efficiently? does it sounds like a vacum cleaner?
or does it just flood and rev's drop?

Vacum cleaner sounds, Idle jet is to small, as it also does the first progression, for a test swap the 2 idle jets over and see if it gets better.

if it floods then probably your pump jet is to big or your idle jet is to big.

2, Primary MAIN JET

how does the car behave when you are driving it under light throttle? (MAX 1/2 throttle)

if you beleive it is too lean change the secondary main jet (Other side of carbi) with the primary jet? does it improve?if not change it back, then try the Air correction jet. Does this help?

once you get the primary side correct the secondary side is roughly the same just the jets idle, Main nedd to be about 1 or 2 sizes bigger depends on applications, and aircorrectly may need to vary a little either way,

Modifing jet sizes can be done,
your will need a set of jet drills ( Weber suppliers can sell them) or a set of fine engineer's drills.

Solder up the jet whole if it is to big and re drill making sure that don't affect the entry and exit these need to be the same as the jet was, so be careful not to block these with solder as they effect the flow greatly.

when you get it pretty close go and get it dyno tunned, and see how close you actually were.

What you want to end up with a responsive reving engine cleanly with out hesitating.

BUT don't expect to be able to be in 4th gear at 40kms and floor it and it will pick up and go, the 32/36 is a mechanical carbi, and when you flatten it, it will open right up and poor fuel in, probably way to much for the current engines RPM rate, so squeeze the throttle down rather than flatten it and you will soon learn. or just drop it back to 2nd and floor it hahaha


Ben wright has the ultimate knowledge about this, and he has made many prevoious posts about this topic, maybe have a good search,

cheers
Eggy

[WAY2LOW]

cheers for all that ill give it a try!!

thanks again

justin

[Ben Wight]

The carb sounds fine, it only pumps fuel down the primary side, as it has mechanical secondaries. If it sprayed fuel down both sides, and you only put your foot down halfway, you would get a pool of fuel forming in the second barrel.

The mains should be both 140, and the air correctors around 175 and 165 for the primary and secondary circuits respectively.
When you say its not running right, what exactly do you mean?

Ben Wight