Tipidave Posted March 23, 2021 Author Report Share Posted March 23, 2021 Could i take out the drain tube from the manifold and try to tap a vacuum gauge there? ot could i take off the vacuum advance feed on bottom of carb? Link to comment Share on other sites More sharing options...
Colin Lindsay Posted March 23, 2021 Report Share Posted March 23, 2021 9 minutes ago, Tipidave said: Could i take out the drain tube from the manifold and try to tap a vacuum gauge there? I doubt it would work as a vacuum gauge take-off; if it allows that amount of suction it would seriously affect the running of the engine when it's just an open drain pipe. You can (used to be able to, anyway) buy adaptors that go between the carb and the manifold for a gauge takeoff. Found one! https://www.ebay.co.uk/itm/Solex-New-Carb-Vacuum-Gauge-Adapter/254578366469?hash=item3b460d9805:g:bxEAAMXQI5tRhN0T Link to comment Share on other sites More sharing options...
Tipidave Posted March 23, 2021 Author Report Share Posted March 23, 2021 7 minutes ago, Colin Lindsay said: I doubt it would work as a vacuum gauge take-off; if it allows that amount of suction it would seriously affect the running of the engine when it's just an open drain pipe. You can (used to be able to, anyway) buy adaptors that go between the carb and the manifold for a gauge takeoff. Found one! https://www.ebay.co.uk/itm/Solex-New-Carb-Vacuum-Gauge-Adapter/254578366469?hash=item3b460d9805:g:bxEAAMXQI5tRhN0T Fab. I have just made a purchase. I didn’t know that existed Link to comment Share on other sites More sharing options...
Colin Lindsay Posted March 23, 2021 Report Share Posted March 23, 2021 Now: the interesting question is: do you fit it in addition to the insulator block, or in place of it... Link to comment Share on other sites More sharing options...
Tipidave Posted March 23, 2021 Author Report Share Posted March 23, 2021 Ha yes... initially it will need to be instead. I do not have long enough studs and imagine it would end up interfering with the bonnet if it keeps going up!! Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 23, 2021 Report Share Posted March 23, 2021 you could lash up a vac gauge from the drain tube it is a small or should be a small hole in the tube so any air in has minimal effect on idle mixtures but for a vac test yes the dizzy take off does not produce manifold vacuum and def wont work . any vac gauge installation will need a restrictor to stop needle vibrations a bit of metal tube sqished with pliers till you get a steady needle if the drain tube has a jetted end (hole smaller than the pipe dia) it may be fine but in the end of the day unclamp the dizzy and rotate to get the fastest idle speed and back it of a bit do this at a raised idle eg 800-1000 so its a bit less than best see what she does then ........... a cheap check pete Link to comment Share on other sites More sharing options...
Tipidave Posted March 27, 2021 Author Report Share Posted March 27, 2021 Time for a bit of an update maybe? I fitted the vacuum take off carb spacer that Colin pointed out on eBay. Works at treat. After a little fettling, with both carb and timing the vacuum at idle has risen from a steady 19 in hg to just under 21 in hg. And is steady.:) I have fitted a new fuel pump from supplied by James paddock. Before fitting i checked the output on the old one and it was 9.5 psi 🙂 The new one is still a tad on the high side at 4psi and fitted directly to the carb it was too much for the float valve ... so i have left the filter king in line adjusted to 1.5 psi. Initial results are that this has solved the problem of fuel leaking after stopping the engine. My guess is that as an earlier contributor suggested, the fuel pump pressure on the input side of the filter was bleeding through after turning the engine off. Mick Dolphin is going to send me an original pump which hopefully will solve the issue once and for all with a rebuild kit and original spring. But for now... off i went up the road, only to find that the main jet was now partially obstructed. In all i have cleaned out the carb three times. Seems to be ok now but wondering when the new ethanol proof fuel line will arrive. Pete you were damn right about those pesky slivers of rubber! Or more like little crumbs. Is there an opinion on whether this issue is likely to re-occur randomly... or once clear does it tend to stay clear if nothing is disturbed? Thanks for all the help so far... getting somewhere now Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 27, 2021 Report Share Posted March 27, 2021 it should stay clear once flushed clear but will return if you pull things apart and make some more of the little sods i would say rebuild with a nylon fuel pipe all through get rid of as many connections as possible for a future project glad theres progress 9.5 from the pump is a bit alarming and even 4 is beyond capabilities of our floats etc this is more of the crap stuff we are supposed to put up with its sad when a 60 yr old unit is still better than a modern repro . why cant manufacturers build to a specification its not rocket science is it. Link to comment Share on other sites More sharing options...
johny Posted March 27, 2021 Report Share Posted March 27, 2021 Dont know Pete, matching a spring might not be so easy. Theres various factors that affect each other and of course the end result such as: grade of steel, tempering it, correct wire size availability (imperial)?, coil dimensions and number plus then final quality control. This obviously all has to be done to a price and also maybe the manufacturer doesnt even think the output pressure is so critical... Link to comment Share on other sites More sharing options...
Tipidave Posted March 27, 2021 Author Report Share Posted March 27, 2021 I am hopeful that if I can get a good old unit then I will be able to make good in the pump department. I have some 1/4 inch copper fuel pipe and if I can work out how to bend it think I will make a run of it between pump and filter....leaving only a short run of flexible from filter to carb. just back from a good run and have to say it is driving very smoothly. Waiting for distributor to come back now... sure that the repro one is no where near correct! Link to comment Share on other sites More sharing options...
daverclasper Posted March 28, 2021 Report Share Posted March 28, 2021 Glad your getting there. Never had to do it, though I understand the copper pipe is easy to bend around anything with a suitable sized radius. Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 28, 2021 Report Share Posted March 28, 2021 you are best fitting a filter in the boot on a herald /vit then you filter the whole system stops crap into the pump if you resist tampering !!!! the slivers will become extinct Ha always check the short rubber hose from the tank suction tube this is out of sight and gets very degraded because its above the fuel level it often doesnt leak but does suck air Pete Link to comment Share on other sites More sharing options...
Tipidave Posted March 28, 2021 Author Report Share Posted March 28, 2021 I will put that in my list of things to do with the fuel system. I have to say that I do not like playing with the petrol supply... so once I am happy I do not intend to continue fiddling! Another good run today and no sign of any leaking fuel on shut down. Link to comment Share on other sites More sharing options...
Tipidave Posted March 31, 2021 Author Report Share Posted March 31, 2021 So here’s the thing... After driving the car into work yesterday with a cheesy smile on my face i thought that i would do the same today. Unfortunately before i could leave the car park this afternoon the car spluttered to a halt. upon investigation the carb bowl was empty.... after some very high tech investigation involving blowing back down the fuel line and listening for bubbles in the tank... the fuel pump came out and upon inspection has well and truly failed. The t piece on the end of the spindle is narrower than the fork in the lever end and so it will not be held in place. The two sides of the fork are separate and. Able to flobble around enough that it cannot be made good. i deliberately avoided buying a cheap Chinese copy and purchased from what i thought to be a reputable dealer. I was re-assured when i was told ‘we have sold hundreds of these and never get returns’. Was i just unfortunate? I think not! Link to comment Share on other sites More sharing options...
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