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AnsweredHot!Carburetor for Techumseh HM100

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Diesel Dave
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2018/08/14 21:54:27 (permalink)
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Carburetor for Techumseh HM100

I have a generator with the 10hp Techumseh engine. It was lunging and surging. I tried the adjustments mentioned on this forum with no luck. I bought a new carburetor that said it fit this engine. However, it does not have the high speed adjustment screw in the bottom of the bowl. I installed it and the engine runs but sputters and wont level out. Will this carburetor work on this engine? It also has an extra port in the body where the choke butterfly is. Do I need a different carb?
Roy
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Re: Carburetor for Techumseh HM100 2018/08/15 01:18:20 (permalink) ☼ Best Answerby Diesel Dave 2018/08/15 14:25:40
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I would go back to the original carb, the new one is probably offshore junk. When you remove the bowl you will see a 'bump' on the center post, it houses the idle passage which tends to plug up. Remove the idle mixture screw then run a tag wire up the passage, the opening is in the threads so will take a little fishing to find. I use a welding tip cleaner.
I know your unit probably doesn't idle down  but runs on the idle circuit until a load is applied and the throttle opens up.
Diesel Dave
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Re: Carburetor for Techumseh HM100 2018/08/15 14:27:44 (permalink)
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Thank you. I'll give that a try. I thought about buying a rebuild kit for the old one as well.
Diesel Dave
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Re: Carburetor for Techumseh HM100 2018/08/15 18:34:49 (permalink)
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Roy, I did clean the low idle port as you suggested. The engine runs smoother at top end and with a load on it. However, when you remove the load the rpms shoot thru the roof. It still has a slight miss and backfire too.
Roy
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Re: Carburetor for Techumseh HM100 2018/08/15 20:28:22 (permalink)
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It sounds like you disturbed the governor setting. With the engine off loosen the screw that attaches the governor lever and  move the throttle to the wide open position. Now turn the governore shaft in the same direction as far as it will go and without disturbing anything tighten the screw.
Diesel Dave
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Re: Carburetor for Techumseh HM100 2018/08/16 21:32:54 (permalink)
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Well I bought a rebuild kit and overhauled the carb. Even knocked out the welch plugs and cleaned those ports. Now the generator tries to run good at high speed but will not idle down. I can run the idle adjustment screw all the way in and the engine does not change. Does this sound like and air leak?
cowolter
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Re: Carburetor for Techumseh HM100 2018/08/19 07:23:54 (permalink)
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For what its worth I have a Garden Way (Troy Bilt) best lawn vacuum with a 3.8 HP Techumseh that I bought it 1993. It has always been a bear to start when it sat from Fall to Fall or even a couple of months. It was one of the first of the carbs without a main jet adjustment and a primer start. It finally got so I couldn't start it without putting gas into the combustion chamber. Because I like the vacuum I spent the roughly $30 for the knock off replacement carburetor three years ago. Bolted it on and it started the first pull and has continued to do that. It never did that with the factory carb. The new carb is better than the original was and has the ability to adjust the main jet built into it. This is the carb Tecumseh shouldof bought from the Chinese all those years ago and they would of had a better engine. 
post edited by cowolter - 2018/08/27 07:01:41
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