I reckon the problem is in the progression holes which are drilled into the body of the carb. These holes are uncovered when the throttle is opened slightly and richen the progression stage. They are probably too small for your engine which will run lean under slight acceleration. By fitting such large idle jets, the problem is masked somewhat. Thats why it got worse when you went down to the 50s. If you are lucky your carbs will have little screws which you can undo and see the progression holes. These are located just behind the idle mixture screw. Some carbs however have a pressed in brass plug which makes it difficult to access the holes.
Give us some more info like what size chokes, main jets, air correction and emulsion tubes you have. Cheers, +--------------------------------------------------------+ | Chris Howard | Email: [EMAIL PROTECTED] | | '69 Datsun 510 | Web: http://turbovan.com/ | | '80 Escort Van SR20DET | Work: http://wattlesoft.com/ | +--------------------------------------------------------+ | Forced induction - 'The replacement for displacement.' | +--------------------------------------------------------+ -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Duncan Shillito Sent: Tuesday, 2 October 2001 6:14 PM To: [EMAIL PROTECTED] Subject: weber tuning listers, i'm having fun trying to achieve smooth slight acceleration with twin 45s on my 2.3 L series. full throttle is good but it backfires through the carbs during slight accel and cruise. i'm thinking that the idle jets are too large and there is too much fuel. i have 55F9 jets but have tried 50F6 - worse. there is a aluminium spacer under the head (starting to leak oil)- achieving 9:1 comp now but over 10:1 without it. any ideas ???? thanks in advance, dunc. Get your FREE download of MSN Explorer at http://explorer.msn.com --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/[email protected]/ --------------------------------------------------------------------- --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/[email protected]/ ---------------------------------------------------------------------
