weber revving problems

[ctrain]

Hey guys, I just rebuilt my weber 32/36 cos a few days ago it started to backfire out the exhaust and carby while driving, the powervalve was torn up so i replaced that and left the jets as it was because the carby specialist said that the current jets are fine for my 1600 2T, anyway we put it back on and it wouldnt start, it would crank, fuel was going into the carby and it was getting spark, so to be sure we replaced the points, spark plugs, and rotor cap, and with some adjusting of the timing we got it to fire, it idles fine but when you accelerate it starts to backfire and struggle holding revs around 2k and upwards and if you go WOT it just conks out, not sure if its flooding though. we played around with the mixture after we got the ignition timing right, i screwed it in a good 6-8 turns with little difference then it ran really shit, too lean, so it turned out the screw and its not changing, im thinking the needle is stuck. can anyone shed some light, this problem all of a sudden popped up in the worst time and i needa get it fixed asap, i do have a new fuel filter so put in, would the old filter be clogged?

any help would be appreciated!

Cheers,
Callum

Oh and also when i was rebuilding the carby it only had one idle jet (main) there is the hole for the secondary jet but it was never there, can it run with only one idle jet?

[w810sc]

Sounds like you might have a vacuum leak somewhere. Check around the carby mounting plate gasket and intake manifold for leaks. You're relying on the motor's vacuum to pull the fuel in through the carby. Spray some carby cleaner around the carby to see if the idle changes, if it does then you know you're close to where the leak is. If you want to do it old school, get a piece of flexible hose and hold one end to your ear and the other around the carby, listen for a hissing noise, when you do hear it you will be around where the leak could be.

The secondary idle jet is for a smooth progression from the primary butterfly being opened all the way to the opening of the secondary butterfly. The leak could be coming from this hole if there's nothing in it.


To help you understand a bit more with diagrams have read here:
http://www.webercarburatori.com/?p=handbook
It got me out of trouble a few times.

good luck.

[ctrain]

thanks mate, i done the old school method today and couldnt find/hear any leaks, also got some carby cleaner and that didnt reveal anything aswell, so i just took it off and put on my new weber 38/38 carby, more powerful then a 32/36 and will be compatible when i turbo it