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Toro 421 Carb causes engine to race (Tecumseh engine)


acbeer's Avatar
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Join Date: Dec 2008
Posts: 4

12-20-08, 02:07 PM   #1  
Toro 421 Carb causes engine to race (Tecumseh engine)

I have a 2 stage Toro 1980 421 snow blower. I recently replaced the float pin in my carb. Now when the engine runs it at times will take off like a race car. The revs are getting so high I am worried the engine will be damaged. The engine is also using up fuel at about 3 times the normal rate. I am wondering what I need to do to get the carb back to where it ran well last winter. I am thinking it has something to do with the screw under the bowl that I had to remove to replace the float pin. I did not touch the 2 screws on the carb itself when I removed the carb to replace the float pin. Any ideas of how to get this thing to run at a reasonable rpm?

Does anyone have the manual for this in PDF? Toro does not have it electronically.

Thanks!

 
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indypower's Avatar
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12-20-08, 03:11 PM   #2  
Why did you have to replace the float pin? I have never seen 1 break.
Did you take the carb off the engine when you did this?
I think when you did that, you did not have gotten the needle seated correctly. Thus using gas @3 times normal.
And yes, over-reving will end up seizing the engine.

 
acbeer's Avatar
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12-20-08, 04:36 PM   #3  
This winter when I started the motor the carb was leaking fuel from the butterfly valve continually like the float was stuck. When I took it apart it did not have a float pin. It may have had a stuck float and when I took it apart I may have dropped the pin. Who knows. I replaced the pin seat and the pin and the bowl screw gasket and bowl seal. I did take the carb off the blower. I am fairly sure the needle is seated correctly, but I am less sure that the bowl needle is adjusted correctly. I am unsure what this the needle at the bottom of the bowl does, so I am unsure of how to mess with it. The motor tends to start up okay but once it warms up it starts to rev higher and higher.

Thanks for any help!

 
indypower's Avatar
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12-20-08, 04:53 PM   #4  
The needle on the bottom of the bowl is high speed adjustment.
Turn it in until it is LIGHTLY seated all the way in. Back it out 1.5 turns.

 
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