attwood65 Posted July 12, 2017 Report Share Posted July 12, 2017 Installed professionally refurbished carbs and distributor. Ran fine for 6 month then stopped working. Stored for 18 months. Now trying to start. Electrical system checked and spark at plugs Flushed out old fuel Connected fuel pipe to new can of petrol Fuel pump works, fuel coming out of pipes going into carbs when I turn engine over Plugs NOT wet with fuel Do I have a carb problem. Any ideas, driving me nuts trying to get started Thanks Link to comment Share on other sites More sharing options...
Paul H Posted July 12, 2017 Report Share Posted July 12, 2017 Have you tried spraying carb cleaner direct into carbs , if she starts then it's a carb clean down with blocked needle valves a possibility Paul Link to comment Share on other sites More sharing options...
attwood65 Posted July 12, 2017 Author Report Share Posted July 12, 2017 thanks will give this a go and see what happens Link to comment Share on other sites More sharing options...
Guest Posted July 12, 2017 Report Share Posted July 12, 2017 I think you have answered your own question by a process of elimination. Healthy spark at plugs - excellent fuel pumped in to carbs via pump - excellent no wet plugs - problem The issue must be within the carbs and I think the problem is debris causing it to stop initially. Then being left for 18x months has allowed the delivery process within the carbs to gum up with the usual results. Paul is correct, you need to do a complete carb strip down thoroughly clean and you should be home. One other point: do you run a fuel filter - if not you should. Regards. Richard. Link to comment Share on other sites More sharing options...
attwood65 Posted July 12, 2017 Author Report Share Posted July 12, 2017 Good idea, will try Pauls suggestion, then looks like a strip down and clean in any case. Will let you know how it goes. Thanks Paul and Richard for the quick replies Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 12, 2017 Report Share Posted July 12, 2017 just stripped some longer standing150s and the needles were seriously jammed in the jets with nasty corrosion never seen that before in all the years of carbs carb cleaner quite useless , had to use a plumbers sulphuric acid to get the goo out of the jet holders and float zone so old gum does exist pete 1 Link to comment Share on other sites More sharing options...
dave.vitesse Posted July 12, 2017 Report Share Posted July 12, 2017 I agree with all feed back, it sounds like either blocked float valves or stuck needles. Before stripping the carbs see if the pistons lift and fall OK. Don't forget to re-centre the needle after working on the carbs. Dave Link to comment Share on other sites More sharing options...
attwood65 Posted July 12, 2017 Author Report Share Posted July 12, 2017 Tried some easy start directly into the carbs. Nothing. Link to comment Share on other sites More sharing options...
Guest Posted July 12, 2017 Report Share Posted July 12, 2017 Not surprised. Next move is to strip it down fully and inspect & clean each component accordingly. Regards. Richard. Link to comment Share on other sites More sharing options...
dave.vitesse Posted July 12, 2017 Report Share Posted July 12, 2017 If the needles are stuck the pistons will not lift and this would stop it starting, even with easy start. This may not be the problem but please check you can lift the pistons by hand and they then fall back. Dave Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 12, 2017 Report Share Posted July 12, 2017 I had a maifold gasket fail and the engine was sucking in air through the gasket rather than fuel from the carbs. It wouldn't fire at all however, easy start worked, briefly. Yes, what Dave says, lift the piston, open the butterfly and squirt it in. Could be a timing problem, Andy Cooke had his timing chain slip around it's gear . What were the circumstances of it stopping working? Link to comment Share on other sites More sharing options...
attwood65 Posted July 12, 2017 Author Report Share Posted July 12, 2017 I was not with the car when it stopped, my parents were running it. One said it just stopped the other said there was a bang! Piston lifts but does not go all the way down (stops about 5mm short). Same on both carbs. Going to strip down carbs and remove manifold/replace gasket. Will also look at the timing Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 12, 2017 Report Share Posted July 12, 2017 You can test the vacuum by puting your hand near the carb air intake while turning the engine over, you should feel the vacuum. You will need long arms or an assistant to do this! I did hear of a guy attaching a post-it note to the carb body and when he turned the engine over the carb grabbed hold of the post-it. 1 Link to comment Share on other sites More sharing options...
dave.vitesse Posted July 12, 2017 Report Share Posted July 12, 2017 If the pistons are not returning to the bottom it may be the needles sticking, require centralising or the diaphragms need replacing. Also check the diaphragm in the Smiths emission valve. I agree with Doug re timing and inlet manifold. Dave Link to comment Share on other sites More sharing options...
attwood65 Posted July 12, 2017 Author Report Share Posted July 12, 2017 Thanks everyone! Carbs striped down, they were all clean inside and looked good. Having some trouble centralising needles. They don't go down the last 5mm when I tighten Link to comment Share on other sites More sharing options...
attwood65 Posted July 12, 2017 Author Report Share Posted July 12, 2017 diaphragm in the Smiths emission valve cracked and has a hole! 1 Link to comment Share on other sites More sharing options...
dave.vitesse Posted July 12, 2017 Report Share Posted July 12, 2017 That would cause the mixture to be very weak. It may be the problem. Dave Link to comment Share on other sites More sharing options...
dave.vitesse Posted July 12, 2017 Report Share Posted July 12, 2017 It may be the diaphragms in the carbs causing problems with centralising the needles. However, try this first - as you do the final tightening work the pistons up and down at the same time. Dave Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 12, 2017 Report Share Posted July 12, 2017 some repro diaphragms are very stiff thick nasty rubbery things , should be quite flimsy and very flexible if they are orig, and swell when taken out a wash with petrol will revert them to size as for the smiths valve you can dummy a get you home from a poly bag to trial it starting depending what the original bang was maybe a compression test is worth considering Pete Link to comment Share on other sites More sharing options...
attwood65 Posted July 12, 2017 Author Report Share Posted July 12, 2017 Diaphragms look fine and are supple. New Smiths emission valve diaphragm on its way, plus gaskets. Checking, timing, compression and vacuum. 1 Link to comment Share on other sites More sharing options...
dave.vitesse Posted July 12, 2017 Report Share Posted July 12, 2017 Well done. Dave Link to comment Share on other sites More sharing options...
attwood65 Posted July 13, 2017 Author Report Share Posted July 13, 2017 Carbs stripped and back together. Manifold and exhaust off. Waiting new gaskets 1 Link to comment Share on other sites More sharing options...
attwood65 Posted July 13, 2017 Author Report Share Posted July 13, 2017 Carbs back on. Still does not start. Plugs dry after firing so I am guessing fuel not getting through to plugs. Any further thoughts, don't want to have to admit defeat and go to a garage! Link to comment Share on other sites More sharing options...
attwood65 Posted July 16, 2017 Author Report Share Posted July 16, 2017 Carbs back on. Still does not start. Plugs dry after firing so I am guessing fuel not getting through to plugs. Any further thoughts, don't want to have to admit defeat and go to a garage! Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 16, 2017 Report Share Posted July 16, 2017 Can you feel suction at the carb air intake when you turn the engine over? Link to comment Share on other sites More sharing options...
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