ignition timing first of carb adjust

Ok about 2 months ago petrol 2/25 series 3 was spluttering like a good un , spent ages adjusting carb with no results , went to garage who slackened bolt turned distributor and adjusted ignition timing and all was well. Landy now only doing 10mpg and overrunning after turning off ,
mixer screw almost needs to be fully out to stop it spluttering ,
question is if I adjust ignition timing again to stop it spluttering will i have more success balancing card idle/mixer , also seems to overheat (according to dash display no other symptoms) when on a short run , could these thing be related?

Thanks

Yup, all the garage have done is advance the ignition but the carb settings look out as well; a case of making it worse rather than better. I'd start from scratch and set the carb to its factory settings and similar for the ignition timing - do you have a workshop manual, its all in there.

No good messing with the carb until the ignition is set correctly as John S says.

OK , That will be my starting point then thanks , ill dig out the haynes

Timing a 2.25 is not completely straightforward. You needit to be running at low idle about 550rpm woth vac pipe off. It then wants to be roughly 6 to 8 deg btdc. Its hard to be exact as you may be experiencing some cetrifugal advance.
Everything must be spot on before touching the carb plus your carb should be in good condition with no air leaks, blockages and floats set up correctly. Strip it and service then set her up. There is a guide on here for a 36iv if you search

I have looked at manual , I have a later style timing pointer so it has to line up with mark on crankshaft pulley , however marker has one point and not 3 possibles as in manual , I'm Assuming I just line it up to that

OK this is straightforward so far ,however manual says turn distributor until test lamp lights with one end connected to the coil lead and the other to earth , however I turn it to both extremes and the light stays on . where exactly should it be connected to the coil lead ? I hat it touching the spade connector in the distributor , am I doing it incorrectly ?

Any ideas please ,??

When the points close the light should go off as the voltage is connected to earth .
Check your points are clean and the small earth wire that fixes to base plate points attach to is sound.
That's provided you have not had electronic ignition fitted.

The bulb should be wired across the points gap. Old timers would trap a ciggy paper in the gap, pull gently whilst turning the dizzy and stop when the paper just started to pull out.
Q1. have you adjusted the gap correctly?
Q2. have you replaced the condenser?

Yep gap adjusted and new condenser , ciggy paper trick worked a treat , one final question , the first procedure in the Haynes was putting you finger over spark plug hole and waiting to feel pressure build up , once I've done this and found correct positioning for pulley and marked it off do I need to do that part of procedure again or was that just to find correct pulley position ?

Dont really see the point of putting thumb over spark hole to feel pressure because you then have to turn crank handle again to line up Mark

Better option is to remove rocker cover and look to see if cylinder 1 valves are both closed and piston approaching TDC.

just wondering though, wouldnt turning the crank pulley to line up to mark change position youve just lined up by putting thump over spark hole and waiting for the pop , can somebody explain this please , thanks.

The cylinder will not pop if valves are open , so when it pops it is coming to TDC with valves closed , hence my comment on looking at valves.

Yes dont confuse tdc exhaust stroke to the compression stroke. One cycle is two rotations and you dont want your spark plug trying to fire on an exhaust stroke!

I just poke a blunt screw driver down the hole and watch that to find ~TDC whilst watching the rockers. Both closed is the turn it should fire on.

Daft question, but you need to set the gap when the points are fully open - whilst having a blonde moment I've set it to be open when it should be closed...that had me scratching my head for a while. A multimeter with dwell setting is a good investment...or electronic points to save lots of re-setting!

Timing is all done now , old problem is back though , Landy kicks back slightly from exhaust approx every minute , not too bad , I've tried adjusting carb , am I right in thinking on Weber top screw is idle and bottom screw is mixture , if this is the case ( which I think it is ) kick back is very bad when mixer screw is 2 1/4 turns from body as recommended and it needs approx another 3 turns out to make noise less frequent , surely that isn't a slight adjustment , also there's a lot of recommendations on where to start with mixer screw , however where do you start with idle screw , some people say all the way out , and slowly screw inwards

Is it fully, warmed up. i.e. have you taken it for a good hard run and done the carb adjustment then. If not then you are just in effect putting extra choke on. The odd burble is normal for these especially when cold or not fully warm and is just dribbles of condensation (petrol) being sucked into the engine. If its just the odd stumble in idle then I'd not worry....unless you like throwing petrol away

They do pop a bit its normal

Just one final question re this , I know where mixture screw should be when starting to tune car (between 1 1/2 and 2 1/4 turns out) , however I have a weber and its not the best , am I right in thinking that idle screw should be fully out when I start tuning and slowly screwed in, concern I have with this is that if I screw it too far out that it will fall out!