Muddywheels Posted February 10, 2015 Share Posted February 10, 2015 Hi- I know Dingo carburetors have been the subject of a recent ( very useful) thread. I wonder if anyone could help with this ? Once my Dingo is running, it runs very well. Idles happily, pulls well up hills- no excessive smoke and the plugs aren't fouling.But- starting it is a complete lottery. If it does start, it will run perfectly. But if it won't start, the only way to get it going is to unscrew the feed to the carb, and stick a cocktail stick down the needle valve aperture. Bouncing the float up and down on the float arm a few times usually then allows it to start. Not a stuck needle valve- it's got a brand new one, and both this ( and the old one) move as freely as it's possible to move. Entire carb stripped down, ultrasonically cleaned and new seals throughout. Plenty of fuel (pressure reduced by adding an extra gasket under the pump,as suggested by Singe) Clean as a whistle fuel lines, right back to the ( reclined) tank. Once it starts, and going on a long run- stopping and starting again a few times is no problem. But run it for 10 minutes or so, and then leave it until the next day- back to the original problem. Any suggestions very gladly received - including recommendations for a suitable modern replacement carb, if that's what it takes. thanks- Alastair. Quote Link to comment Share on other sites More sharing options...
TooTallMike Posted February 10, 2015 Share Posted February 10, 2015 Hi- I know Dingo carburetors have been the subject of a recent ( very useful) thread. I wonder if anyone could help with this ? Once my Dingo is running, it runs very well. Idles happily, pulls well up hills- no excessive smoke and the plugs aren't fouling.But- starting it is a complete lottery. If it does start, it will run perfectly. But if it won't start, the only way to get it going is to unscrew the feed to the carb, and stick a cocktail stick down the needle valve aperture. Bouncing the float up and down on the float arm a few times usually then allows it to start. Not a stuck needle valve- it's got a brand new one, and both this ( and the old one) move as freely as it's possible to move. Entire carb stripped down, ultrasonically cleaned and new seals throughout. Plenty of fuel (pressure reduced by adding an extra gasket under the pump,as suggested by Singe) Clean as a whistle fuel lines, right back to the ( reclined) tank. Once it starts, and going on a long run- stopping and starting again a few times is no problem. But run it for 10 minutes or so, and then leave it until the next day- back to the original problem. Any suggestions very gladly received - including recommendations for a suitable modern replacement carb, if that's what it takes.thanks- Alastair. Hi Alistair, That sounds like an interesting problem. If it's pumping out of the inlet pipe when that is disconnected, then surely it has to be needle valve, float or arm. Is the float arm spindle moving freely, maybe the arm is getting stuck in the 'up' position and holding the needle valve closed? Also, is the float the right way up? - MG Quote Link to comment Share on other sites More sharing options...
singaeger Posted February 10, 2015 Share Posted February 10, 2015 What happens if you give the fuel pump a few squeezes with the priming lever? does that not push a few more drops of fuel past the valve Quote Link to comment Share on other sites More sharing options...
Chrisg Posted February 10, 2015 Share Posted February 10, 2015 as it would appear to run ok once started is the problem in the carb starter unit Quote Link to comment Share on other sites More sharing options...
Muddywheels Posted February 10, 2015 Author Share Posted February 10, 2015 Thanks for the input- much appreciated. The float is the right way up ( did have a pinhole in it but mended and all floating ok) float arm is free- and is the correct way up. The float arm spindle moves freely. Pushing the needle valve down with a cocktail stick, does get the float arm to move up and down, so the float chamber is full of fuel and operating correctly to shut off fuel. I'd agree that it would seem obvious that the needle valve is at fault, but it really does move completely freely- there's no way it is physically sticking.Pumping the priming lever doesn't help- a few turns of the starter motor gets all the fuel pumped as far as it will go- and the priming lever is completely slack. ( fuel pump also stripped down and all new seals/ diaphragm) Suggestion of a problem with the carb starting unit is a good one; but the whole thing has been stripped apart, with all new seals, so not sure what else I could do to this. Overall I must have spent 20 or 30 hours stripping out and replacing the carb at least 5 times and running through every possibility( including electrical)I can think of. It's the unpredictable nature that's so frustrating . At least if it ran badly as well, once it did start; I'd have more of a clue. I'd rather it be running with a more modern carb; rather than looking good ( and getting dusty) in the garage. Any ideas/ recommendations on that score? cheers, Alastair. Quote Link to comment Share on other sites More sharing options...
GeePig Posted February 11, 2015 Share Posted February 11, 2015 Is it parked on the flat or on a slope? trevor Quote Link to comment Share on other sites More sharing options...
Muddywheels Posted February 11, 2015 Author Share Posted February 11, 2015 Hi Trevor- on the flat.Shimmed out the fuel pump with another gasket to reduce the fuel pressure slightly this evening- started, and ran fine. Bet it will be back to square one tomorrow, but let's see. Living in hope...... Quote Link to comment Share on other sites More sharing options...
TooTallMike Posted February 12, 2015 Share Posted February 12, 2015 Hi Trevor- on the flat.Shimmed out the fuel pump with another gasket to reduce the fuel pressure slightly this evening- started, and ran fine. Bet it will be back to square one tomorrow, but let's see.Living in hope...... I'd be amazed if it's excessive pressure from the lift pump bearing in mind it runs fine most of the time. Have you swapped in a known good carb? Will it start if you leave the choke fully in and cover the inlet with your hand to simulate a more conventional choke situation? You may need to pour a tiny bit of petrol in to get it going but on the one I was playing with it would start without. - MG Quote Link to comment Share on other sites More sharing options...
Muddywheels Posted February 12, 2015 Author Share Posted February 12, 2015 Hi Mike- haven't tried that, but I will do. Have to say it started again tonight, but the slightest pressure on the accelerator threatened to stall it, until it warmed up. I don't have a known good accelerator to trial ( and thus rule in/ out) I'm looking ..... cheers Quote Link to comment Share on other sites More sharing options...
Muddywheels Posted February 15, 2015 Author Share Posted February 15, 2015 Ok- an update in case anyone wants to know. Seems to be starting well now; have started it every day without a problem. The only change I've made is to add to the gasket under the fuel pump ( now 3mm) total. So I'll have to say that must have sorted it- the mysteries of the Solex carb. Hope this may be of use to someone else,; and thanks to everyone for taking the time to post their comments. Quote Link to comment Share on other sites More sharing options...
David B. Posted February 16, 2015 Share Posted February 16, 2015 (edited) Ok- an update in case anyone wants to know. Seems to be starting well now; have started it every day without a problem. The only change I've made is to add to the gasket under the fuel pump ( now 3mm) total. So I'll have to say that must have sorted it- the mysteries of the Solex carb. Hope this may be of use to someone else,; and thanks to everyone for taking the time to post their comments. Prior to this fix did it have a tendency to wet the plugs on tickover at all or were they running clean ? Edited February 16, 2015 by David B. Quote Link to comment Share on other sites More sharing options...
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