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Lumpy tickover
Posted: Mon Sep 01, 2014 1:06 pm
by Offshore
The tickover on my 1970 Traveller is a bit lumpy and stuttery. Runs smoothly when revving or pull the choke out 1/4 inch.
Should I turn the low speed idle up or have I got a misfire or airleak?
Car runs well enough otherwise.
Re: Lumpy tickover
Posted: Mon Sep 01, 2014 5:00 pm
by dalebrignall
see what happens if you speed up the idle a touch , whats the oil leval like in the carb
Re: Lumpy tickover
Posted: Mon Sep 01, 2014 5:05 pm
by The vast minority
As above
if your tickover is too slow it will do this, you don't say its too slow though so it might be running lean.
Al
Re: Lumpy tickover
Posted: Mon Sep 01, 2014 9:42 pm
by bmcecosse
You have to set this up yourself! Increase the idle slightly - then adjust the mixture up/down for best idle - then drop the idle speed and re-adjust if necessary. The ignition timing can also play a part in idling - so both mixture and timing have to be adjusted together to get the best settings for your engine !
Re: Lumpy tickover
Posted: Tue Sep 02, 2014 7:02 am
by kennatt
pulling the choke would indicate too weak,screw the nut under the carb out slightly and see what happens then.
Re: Lumpy tickover
Posted: Tue Sep 02, 2014 8:47 am
by Offshore
Hi. Thanks for the replies.
Oil level in dashpot is regularly topped up including last Saturday.
Timing was set by the local garage at 10 degrees BTDC and some of the timing marks or something were missing/snapped off apparently.
Will certainly turn the low speed idle up a bit. Car smelt rich this morning getting out of it in the office car park when reversed against a wall.
Garage has set the mixture twice for the price of a pint but both times been really rich. I've weakened it since and feel I've got it roughly right. Did a plug chop a couple of weeks ago. I thought the plug looked on the weak side - father in law didnt. Richened it a flat anyway.
Birthday in a couple of weeks so along with a set of nice shiney stubby spanners, have asked for a Gunson Colourtune - see how we go with that.
Re: Lumpy tickover
Posted: Tue Sep 02, 2014 8:58 am
by bmcecosse
10 degrees before is far too advanced.... Is the vacuum advance working? Does it 'pink' ? Don't waste money on a Colourtune!! You test the mixture with the little lift pin - it's FREE ! But that is only the idling mixture - and not that important . The dashpot doesn't need 'regular' topping up - once every 3 months is plenty.....it only needs a small amount in there - not filled to the top. What does 'rich' smell like ? Running mix is determined by plug colour after a good run (no idling -switch off and coast to a halt) - should be 'beige' colour - not white (weak) or brown (rich).