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Low tickover after accelerator lift-off on Weber

Posted: Wed Sep 22, 2010 2:40 pm
by hyperdrinky
Hi guys,

needing a little advise. I fitted my Weber about 6 months ago (which I love, as most of you do) and need a little help with fine tuning. The car is running fine but I've noticed the when I lift off the accelerator the revs drop down to around 400 for a few seconds before returning to normal tickover. I've read a few blogs on the internet that the spark timing on the dizzy should be a little further advanced than with the standard carb and was hoping someone on here could confirm, or advise me on a possible solution.

Thanks

Re: Low tickover after accelerator lift-off on Weber

Posted: Thu Sep 23, 2010 4:27 pm
by fonzooorooo
yes. more advance. I set my timing up using Nate's advice - "advance it till you hear it pinking under load, then back it off a bit"... Then I set the mixture and idle, adjusting both at once with a CO analyser. ("book value" is 1% mine's at 1.6%... an earlier excercise in wasting money saw me taking to a local expert who set it up at 4.5% CO saying "you need to run the weber richer" ... well... perhaps...)

Oh, and I get the same miles/pound (matters more than MPG!) from super as I used to on regular unleaded... and that choice affects how you set the timing...

Re: Low tickover after accelerator lift-off on Weber

Posted: Thu Sep 23, 2010 10:25 pm
by hyperdrinky
Thanks, my timing is set bang on just now so will advance a bit.

Slight issue. I don't know what pinking sounds like. I've probably heard it but I can't say for sure.

Re: Low tickover after accelerator lift-off on Weber

Posted: Fri Sep 24, 2010 8:34 am
by fonzooorooo
it's a high ish pitched "a tac-a-tac-a-tac" sound when the engine's under load. You don't want ANY at all... so think of the most strenuous bit of road you can and tune it out there... (accellerating up a hill in the higher gears etc.) I found the Ashby bypass handy - long enough uphill bit that you have time to listen once it's in 5th at 50 and still accelerating, with a roundabout at each end and a farm entrance to stop and spanner in at the top(!) not useful info if you're miles away - but you get the idea!