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I have a L8 that is not running. I took the carb apart to clean in and the venturi fell right out. What should I do to fix it? It also has weak spark. It had no spark so I cleaned the points and not it has weak spark. When I crank the engine with a spark plug tester on it, it has decent sparks when the mag snaps 2 times then it shows a continuous weak spark. This happens every time I try it. Any thoughts?
 

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The venturi should come out easily and that is normal, it just sits in the carb body. Do a soak cleaning and blow out all passages with high pressure air.

On your spark, have you tried a new set of points and condesor? Have you tried a new Autolite sparkplug? Autolite 3076 for the slant plug, 216 for the upright.

Todd White has parts for Wico magnetos and Zenith carburetors,
http://gtgravelyparts.com/zenithcarbs.html

Roger,
 

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Inspect all of your battery/starter electrical cables and your spark plug cable as well. If any of those items are original to the tractor, they're way overdue for replacement anyway.
 

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The weak spark condition you describe is indicative of a bad condenser. Just replace it.

The venturi is supposed to fall out. It is the way it was made. When assembled, the venturi is clamped tight.
 

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I am going to give the mag a overhaul.
Are the bearings bad? If not then I would not touch it other than to install a new condenser and possibly points.
 

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I have seen one old cast iron carburetor where the shoulder on the outside of the venturi had worn away so bad that it dropped down into the lower body of the carburetor instead of sitting in/on the cutout for it. That sounds like what was in that post.

If that is your problem, it would be easier to replace the venturi. I have one if needed.

As Richard mentioned, check the throttle shaft bushings. If you have noticeable play side to side on the throttle shaft then you are probably sucking air around the shaft, and you will never get that caburetor running right.

Roger,
 

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I have seen one old cast iron carburetor where the shoulder on the outside of the venturi had worn away so bad that it dropped down into the lower body of the carburetor instead of sitting in/on the cutout for it. That sounds like what was in that post.

If that is your problem, it would be easier to replace the venturi. I have one if needed.

Roger,
That was mine, even had a nice little indention near the jet where the venturi was jumping up and down. It took abot 10 minutes to drill and tap the holes for the set screws. She still works good.
 
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