Hard Starting Tecumseh 3hp
I have a 3hp Tecumseh that I have a devil of a time starting. The old carb kept leaking, so I replaced it with a diaphragm choke type that I bought from another member. It also has the both mixture screws. With just the choke closed, it won't fire at all. With a shot of carb cleaner I can get it started. Or if I cover the carb intake opening with my tumb and choke off all the air I can get it started, though I have to be careful not to flood it. Once it starts it idles and accelerates fine. I don't have an air filter on it at the moment. Thoughts? Suggestions?
how did it start with the other carb ? you might have another problem like a weak spark or even a bad plug. I have had engines that wouldn't fire but when I put a different plug in them they started right up. It seems strange that it won't fire with the choke closed. where is the throttle lever on the carb when you try to start it ? open or closed ? most tecumseh won't start if the throttle is open too much. My hs 35 will start with the choke closed and the throttle open about 1/4 of the way but it doesn't have a governor hooked up. I'm telling you this just in case your governor is holding the throttle butterfly open too much and making it hard to start.How is the compression on your engine ? if it is too low that could make it hard to start too
I've tried it with the throttle open or closed. Doesn't seem to make a difference. I haven't checked the compression with a guage, but I did pull the head off and check the cylinder, and it's clean as could be. No scoring or excessive wear. I suppose I should try a different plug, just to make sure. Just seems really odd. I could get it started on the old carb, but it would drip fuel.
did you try replacing the float and needle seat seal on your old carb ? maybe if you can fix it and get it to stop leaking . I mentioned the compression because I had a briggs that was real hard to start and would only start with ether. It turned out to have a burnt exhaust valve. you can judge the compression by pulling the engine over slowly , you should be able to feel resistance as it hit a compression stroke. It could be something simple like carbon on the valve seat or a valve that doesn't close all the way. Another check is put your thumb over the exhaust port and then the carb as you pull the starter. basically you are checking if the valves are leaking, you will feel it suck air in the exhaust side or blow out on the intake. I hope this helps you track down the cause of your problem
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