i have an old sears tecumseh on a manco mini bike, and it wont run right. it starts and idles fine but when i give it gas it wants to go at first, but then it cuts out and sputters and caughs and has power surges on and off. it acts like its running out of gas! but its getting plenty of gas and i totaly cleaned out carb like 4 times and replaced everything like needle and seat and diaphram and it shouldnt have any leaks, but its acting like its not sucking enough gas! plz hepl its a 3.5 hp sears tecumseh with a diaphram carb and i think its like an h22 or h35. and the number says 143 784112 im thinking of buying a new carb for it, but i hate to pay 60 bucks and have it do the same thing. cuz it dont look like anything is wrong with the carb. it looks fine but it sure acts like its a carb problem!
old sears tecumseh wont run right plz help!!
Remove your fuel bowl retaining nut/bolt. Clean it real good, I think you have a hole clogged. The hole I'm referring to, is called the idle fuel transfer passage. It's real small. There are also bigger holes on the bottom, they are fuel inlet ports. But it's the smaller idle fuel transfer passage most people don't see. I'll look for a reference pic for you.
Page 330 of this link shows what I talking about.
Outdoor Power Equipment (ED Version) - Google Book Search
Outdoor Power Equipment (ED Version) - Google Book Search
Oops, my bad. :doah
idn't catch that in your post. Oh well, this link is for Tecumseh manual in PDF, so you need adobe reader. Look on page 14 (carb troubleshooting).
www.cpdonline.com/692509.pdf
idn't catch that in your post. Oh well, this link is for Tecumseh manual in PDF, so you need adobe reader. Look on page 14 (carb troubleshooting).www.cpdonline.com/692509.pdf
yes i have adjusted the mixture screws. ive tried the stock settings full turn out and ive tried turning them in till it dies, but no matter what i do to the screws it seems to run the same or just die. it seems rich to me too, but making it leaner didnt help unfortunatly and i looked at the points like someone else said, but it doesnt realy have points. it just has a flywheel and a coil and these magnets, and i cleaned all that stuff up, but still runs the same.
and i looked at the points like someone else said, but it doesnt realy have points. it just has a flywheel and a coil and these magnets, and i cleaned all that stuff up, but still runs the same.If the diaphragm and gasket get put in incorrectly (reversed) it can allow too much fuel into the carb. Also, if the needle valve doesn't seal properly it'll leak excess fuel into the carb too. There's a check valve in there too (it allows fuel to flow one way and not the other) that could be stuck.
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ok i took the cover off and the flywheel. but there is no points anywhere that i can see. there is just a magnet and a coil. but there is two empty holes underneath the flywheel that look realy clean like something was just taken off of there! is this where the points are supposed to be?? you can see the holes im talking about in these pics i hope
Thats probably an electronic ignition coil which does not require points that has been added to your motor.
Your missing your original flywheel,coil,points and condensor. You need to find a parts breakdown picture to see everything your missing. The flywheel you have probably matches that coil you have now. But who knows if its set up with the correct timing.
Your missing your original flywheel,coil,points and condensor. You need to find a parts breakdown picture to see everything your missing. The flywheel you have probably matches that coil you have now. But who knows if its set up with the correct timing.
You have a coil (thing with the spark plug wire) and don't need points, put the fly wheel back on, theres a magnet on the outside of the wheel where it contacts the coil. Stick a standerd (paper) business card between the magnet and coil , that will be your popper gap. You can adjust by loosening the bolts on the coil.
Now go back to the carb because that is your problem, make sure you put the diaphragm gaskets in the right way.
Now go back to the carb because that is your problem, make sure you put the diaphragm gaskets in the right way.
Some of the walbro carbs on these engines were not rebuildable. Some of the cheaper carbs were assembled then the jet holes were drilled through the case and jet. When these carbs are taken apart and reassembled, it is impossable to get these holes to line up. New carbs are available (BUT they are expensive, about $90, and they are made in chezkoslovakia).. I have a tecumseh with no points and it runs very well. If there is a small wire coming from the coil, make sure it is not grounded. That is the kill wire.