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weber carb adjustments

Posted: Sat Jun 27, 2009 4:46 pm
by walkinginperu
Sorry to ask this question - I know it's probably floggin a dead horse!
I replaced the carb to manifold gasket on the weber today as it had a slight split in it. On starting the car again it ran awfully, so i tried readjusting the CO mixture and idle speed screws but i think i've just made it worse. :blush:
Am I right in thikning that adjusting the mixture screw should change the engine speed? I thought only a small turn of the screw should make a big difference to the engine speed, but it doesn't seem to make much difference. If anyone is near leamington spa and knows what they're doing, then I'm happy to provide a few cans of beer :beers: !

Alternatively, if anyone has a 1.6 running on a weber and can tell me their settings (in number of screw turns) that would be even better! Cheers

Re: weber carb adjustments

Posted: Sat Jun 27, 2009 5:50 pm
by go-for-it1
Hi, I don't know if you have the Weber installation instructions, there is a section on them which tells you how to basically set it up. I tried to cut and paste a JPeg into here but it is too big a file so if you PM me your email address I will mail you with them as an attachment. It doesn't say on the instructions but initially set up the mixture screw at about 1 and a half turns open (anticlockwise), then follow the instructions to set up the idle. Also make sure you have reconnected any vacuum hoses before starting as they will suck in air and weaken the mixture.
regards
Rob

Re: weber carb adjustments

Posted: Sat Jun 27, 2009 6:21 pm
by james butler
yeah i had this prob u can only get the carb set up rough if you havent got a gas analyser. have you made sure you have reconnected all pipes and such properly? any thing left off meks a difference. after fitting my weber i had my rocko running sweet but wen i took it for mot it failed on emmisions. put it on the gas analyser and all it took was half a turn on the fuel mix screw to bring rite back down within tolerance. best bet is to tek it to a reliable garage pref with a gas analyser and get them to tune it. at least then its done properly.

Re: weber carb adjustments

Posted: Sat Jun 27, 2009 6:32 pm
by walkinginperu
Thanks for the help guys. There are a couple of lugs where there used to be hoses (on the original inlet) which aren't blokced off, but the car was running sweetly before and flew through MOT in January. Which vac hoses should be connected?I'm not sure if any are to be honest, i followed the weber instructions when i fitted the kit, so anything that should have been connected would have been obvious i guess? :dunno:

Re: weber carb adjustments

Posted: Tue Jun 30, 2009 9:19 am
by roccodave
there are 2 connected from the one way valve on the servo pipe
1) to the back of the carb
2) to the distributor

Re: weber carb adjustments

Posted: Tue Jun 30, 2009 9:33 am
by walkinginperu
Cheers roccodave, i'll have a look tonight!