Pete Lewis Posted January 6, 2017 Report Share Posted January 6, 2017 Somethings making duplicate posts Aidan youve managed 5 will drop a note to the mods pete do make sure any electronic unit does keep the output constant not just a dropper the idea is to give the gauges a constant feed regardless of the charge or battery voltage variations you get in a drive. Pete Link to comment Share on other sites More sharing options...
Bordfunker Posted January 6, 2017 Author Report Share Posted January 6, 2017 I can only see one post from Aidan but a load of duplicates from Casper, very weird. Aidan that would make sense that they have replaced the bi-metallic strip with a solid state device, given how cheap the latter appear to be. On the topic of earthing the speedo, I noticed last night that I have a black wire with no connector hanging freed from the loom behind the speedo. Is this possibly the errant earth wire? Karl Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 6, 2017 Report Share Posted January 6, 2017 I have asked for duplicates to be dumped so thats likely to happen when kevins finished his coffee Soinds like youve found it, the earth normally has a eyelet to fit under the knurled knut pete Link to comment Share on other sites More sharing options...
Bordfunker Posted January 6, 2017 Author Report Share Posted January 6, 2017 Thanks for that Pete. I have at least one other earth lead hanging loose behind the dash. There were three at one point, but I worked out that one of them ought to be connected to the interior light fitting. That should at least be an easy fix. Karl Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 6, 2017 Report Share Posted January 6, 2017 There could be more than one on the speedo nut, Ive got to fit a speedo to a local car ,, took out the siezed a few weeks ago, will I remember what goes where......hmmmm!! pete Link to comment Share on other sites More sharing options...
Bordfunker Posted January 6, 2017 Author Report Share Posted January 6, 2017 Pete that is where a photo is worth a thousand words! I managed to get the Herald started this afternoon, it's not a consistent starter, and doesn't want to idle particularly. I've tried adjusting the idle speed and the mixture as per the workshop manual, but to no avail. I think I might have to call in a professional to set the carb up properly. Karl Link to comment Share on other sites More sharing options...
AidanT Posted January 6, 2017 Report Share Posted January 6, 2017 Sorry about the duplicates frozen internet Grrrrr Aidan Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 6, 2017 Report Share Posted January 6, 2017 Take the slow running jet out and clean it , located half way up the carb body engine side if the throttle is too open the idle circuit doesnt work and nothing will adjust but if it fires with throttle open but dies at idle then suspect the slow run jet is blocked They are a trunkated jet try not to poke the debris into the jet body and it must seat in the carb body when screwed back in.. worth make sure all the small drillings in the top joint face and where they exit near the throttle plate are clear. Link to comment Share on other sites More sharing options...
Bordfunker Posted January 6, 2017 Author Report Share Posted January 6, 2017 I'm having to start the car on full choke, and then push the choke back in immediately and then blip the throttle to keep it from stalling, which matches your description. I checked all the other jets, and took the top off the carb to check the float chamber, all of which were clean and clear. I would have checked the slow running jet if I'd known about. Something for me to sort over the weekend. Thanks Karl Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 7, 2017 Report Share Posted January 7, 2017 In the body are some chambers that take air or fuel they terminate in the top face under the top cover and exit as small holes near the throttle plate these control idle mixure and air flow and the vac take off its easy with age these get blocked , if you are playing give them a blow though or a very careful prod with soft wire some slow run jets are able to seperate , think webbers do , but yours will be a solid jet ofetn the crap stays inside it make sure the choke flap is free, there is a small spring to allow air flow to let the flap open and chatter as it cranks and fires,, give closed flap a poke with finger it should open a little and self close pete Link to comment Share on other sites More sharing options...
68vitesse Posted January 7, 2017 Report Share Posted January 7, 2017 Seem to remember my Herald 1250, first car, had an accelorater pump jet and you had to be carefull not to lose the ball bearing that acted as a nonreturn valve. This was over fourty years ago so could be wrong. Regards Paul Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 7, 2017 Report Share Posted January 7, 2017 no youre correct, generally located under the spray nozzle, also has small 0 ring to seal it Link to comment Share on other sites More sharing options...
Bordfunker Posted January 7, 2017 Author Report Share Posted January 7, 2017 Thanks for the additional info. This afternoon has been spent stripping down the carburettor and giving everything a good clean. Here we are with the top removed, and prior to removing various jets and cleaning them out with some of my airbrush cleaning brushes, which are bendy enough to go around the swan neck, but firm enough to dislodge any muck. I can confirm the existence of both O-ring and ball bearing beneath the swan neck, and no I didn't lose them! The slow running jet was removed, and had the tiniest sliver of muck hanging out of the nozzle, which was gently removed. The jets then all got a blow through with air from my airbrush compressor, with the pressure set to 90. With everything clean I reassembled the carb, and put it back on the manifold. Truth time, would it start? Yes!!!! Not only that it kept running! I had a play with the idle speed and the volume control screw, and it now idles beautifully. Next challenge, take it out for a spin. Fine up to about 35, then it starts to pop and bang and feel like it's running on 3 cylinders. I need to check the plugs to see if aren't firing properly, if they are all OK, then I'm assuming a timing fault or the points. Any advice gratefully received, as it has been invaluable to date. Karl Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 7, 2017 Report Share Posted January 7, 2017 Its brilliant when the simple things solve a major hic up and diy has saved you being fleeced you've had previous plug trouble, are these new or used, plugs life and soul of the engine the oiling may be due to none starts or crap old contaminated fuel someone in the past tops up with fuel from a can with oil in it and problems persist for ages old trick cook the plugs blow lamp or oven and fit them hot . but fit new so in known state , is better than trying plugs that only look like a plug but wont perform like one Link to comment Share on other sites More sharing options...
Bordfunker Posted January 7, 2017 Author Report Share Posted January 7, 2017 Pete, these plugs are new NGKs so should be OK. One of the old ones I removed cracked in half on removal! I gave all the plugs a good clean up with a soft wire brush after the run this afternoon, and 1 & 4 were muckier than 2 & 3. Not sure what to make of that. Karl Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 7, 2017 Report Share Posted January 7, 2017 Guess thats down to the manifold and the split airway in the head have you done a compression test , tappets all got a gap? 0.010" as this is a downdraft carb is the manifold drain tube ok , it should have a restricted jet like end so a little air will be sucked in but it drains excess fuel from any flooding and poor starts on choke including any perculation from the jetting when switched off . the car sounds like it needs a good long cruise to clear it all out, if you get it to run that long pete Link to comment Share on other sites More sharing options...
Bordfunker Posted January 8, 2017 Author Report Share Posted January 8, 2017 Tappets will be one of next stops alongside the timing. The rocker cover hasn't been removed in a while as it is practically welded on, so it's anyone's guess when the tappets were last set. I'll need to take the rocker cover off to check the timing, so might as well learn about checking tappets at the same time! Thanks Karl Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 8, 2017 Report Share Posted January 8, 2017 you dont really need to seal the gasket , some glue the thing and yes its cemented in place, thn ge tin cover and gasket face are not the best design with little gasket location /retention abilities if you put a alloy cover on your Easter wish list get a club neoprene everlasting gasket to go with it and whilst removal is not a monthly check it will not leak and will pop off 'just like that' im often in your area as sister lives in Bloxham, if you get stuck shout !! maybe in the spring i can arrange some more training days for any visitors to sunny luton pete Link to comment Share on other sites More sharing options...
Bordfunker Posted January 8, 2017 Author Report Share Posted January 8, 2017 Not had a chance to do anything major today, however I did exhume the 'old' plugs, well 3 of them at least as the 4th had broken in half! These were then thoroughly cleaned, first with a wire brush, and then with cellulose thinners on a cotton bud and kitchen towel. Here we are with 2 out of 3 cleaned. You can see how mucky these were getting. After clean up, these were re-installed, and one of the in situ plugs given the same clean up treatment. Before firing up, I slackened off the mixture using the screw on the bottom left hand side of the carb, which should hopefully stop the fowling of the plugs. I'm pleased to report that she started on the button! Next up will be a replacement air filter, as the current one is very grubby, which probably doesn't help much either according to the Haynes manual. If the weather is half decent tomorrow, I'll try taking her out for a spin. Karl Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 8, 2017 Report Share Posted January 8, 2017 The mixture screw controls an air bleed to the idle circuit, unscrew richens tighten weakenswith all that oily stuff up the threads , something is not happy , not firing , or sickif you get a run check them once its been up to temp for a good runpete Link to comment Share on other sites More sharing options...
Bordfunker Posted January 8, 2017 Author Report Share Posted January 8, 2017 You're quite right I got that the wrong way round, however I have adjusted it the right way, and slackened off the mixture so that choke is actually required from cold! Hopefully I'll get a chance to go out for a drive tomorrow. Karl Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 9, 2017 Report Share Posted January 9, 2017 The mixture is only adjustable by the idle circuit, you cannot make any changes to the main normal running thats controlled by the jetting. once you open the throttle plate a little the idle circuit ceases to operate, that why a fast idle will not give any changes in mixture adjustment to the tapered screw. the choke flap on some you can alter the automacity spring to give more flap load or less , a sort of winter summer setting , normally wind the small spring over some ratchet teeth on the flap lever The flap must be free to chatter open a bit as each piston sucks , it should open the flap when you rev up a bit The mixture screw wants to be set to best idle amd then screwed in to drop the rpm by about 50 so you are just at the weak side of best , not the rich side of best pete Link to comment Share on other sites More sharing options...
68vitesse Posted January 9, 2017 Report Share Posted January 9, 2017 Again from distant memory on my first car, a Herald 12/50, could not get it to idle well as the tapered screw was worn, the tapered part was waisted, not a straight taper. Why can I remember forty years ago but not last week?. Regards Paul Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 9, 2017 Report Share Posted January 9, 2017 Paul ,yes they do seem to wear or is it due to getting overtightend in a previous life Im sure Doug will have the reasons for remembering a tapered screw here we go again wrong forum pete Link to comment Share on other sites More sharing options...
dougbgt6 Posted January 9, 2017 Report Share Posted January 9, 2017 Ah yes, the skinny prison guard. I thought we agreed never to mention him again! Link to comment Share on other sites More sharing options...
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