Carburetor repair

   / Carburetor repair #1  

AviEst1995

Member
Joined
Mar 22, 2021
Messages
35
Tractor
Kioti LB2204
Can someone help me to understand what it is that I’m holding does on this carburetor? I know that right below it is my throttle and a little down to the left is the choke. Also this engine only idles with full choke and then barely wants to run past idle but I’ve noticed playing with the throttle and that lever from back here I can get it holding higher rpms a bit better.
 

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   / Carburetor repair
  • Thread Starter
#2  
Can someone help me to understand what it is that I’m holding does on this carburetor? I know that right below it is my throttle and a little down to the left is the choke. Also this engine only idles with full choke and then barely wants to run past idle but I’ve noticed playing with the throttle and that lever from back here I can get it holding higher rpms a bit better.
This is what I’m holding.. pic didn’t join first post sorry.
 

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   / Carburetor repair #3  
It is the linkage which opens and closes the butterfly going to the intake (between the intake and carb) it should be connected to the throttle handle in some manner to allow more air/fuel mixture to go to the cylinders.
 
   / Carburetor repair
  • Thread Starter
#4  
It seems to be stuck open the way it is now
 
   / Carburetor repair #5  
The linkage hooked to the carb. should be attached to the engine's governor. Sounds more like a governor problem, rather than the carb.

On other engines, common problems having the same symptoms would be stuck governor flyweights, broken thrust bearing, not allowing to transfer the action of the flyweights to the governor arm, that the rod you're holding controls the throttle shaft on the carb. Third, would be a broken spring which holds the forks of the Gov. control arm against the thrust bearing. Unless it has set for years, I'd suspect the last two items.

Here is an exploded view of a governor on a C-123 International Harvester engine. Schematic, Manuals, Specifications and Diagrams for Governor and connections, 100, 100hc, 130 and 130hc tractors | Case IH | MyCNHi US Store Although different, they all work on the same principle, and may help understand the second paragraph above..

 
   / Carburetor repair
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#6  
Thank you! Would the governor have anything to do with how it only runs when the choke on? I took apart the carb and cleaned it as much as I could and it still will only run on choke but I am able to rev it up now unlike before when it didn’t want to go past an idle.
 
   / Carburetor repair #7  
Probably not. Looking at the first picture more closely, I'm seeing what appears to be 2 fuel filters. Looks like it's been ages since they've been replaced. I'd be tempted to remove the fuel line at the outlet end of the second filter, and see what kind of fuel flow you have. Should be a decent stream, not just dribbling. If it's a weak stream, remove the fuel line from the inlet end of the first filter, and check for fuel flow. If it's a good stream, then the old fuel filters may be part of the problem. If it's weak, start at the fuel tank connection. Can't see if your tractor has a sediment bowl or not. If it does, there "should" be a fine screen above the bowl. If not, it's letting contamination go into the fuel filters. Seeing two, tells me there maybe a lot of crud in your fuel tank.

There's definitely a fuel restriction if you need to choke it, to keep it running. Could be some particles came through the fuel filters, and are partially plugging the main fuel adjusting screw, or finer dirt has plugged the little cross drilled holes in the discharge nozzle, that picks up fuel out of the carbs. bowl, and delivers it to the venturi. It will need to be removed to clean those holes. A strand of automotive wire makes a good cleaner, or, a bristle plucked from a wire brush works too. Just be careful removing the discharge nozzle, as there's probably a small gasket that seals it where it seats in the carb.. If you're careful, you won't damage it, and it can be reused.
 
   / Carburetor repair #8  
Looks like a Marvel-Schebler carb, very easy to disassemble and clean. Most were cast iron and rust would cause problems all the time if not cared for, later models were aluminum/pot metal. Having to choke it to run is a classic symptom of a fouled carb (or possibly a vacuum leak). Carb kits used to be pretty inexpensive, some model floats are about impossible to find - good luck !!
 
   / Carburetor repair #9  
What tractor model is this carburetor on?
 
   / Carburetor repair
  • Thread Starter
#10  
It's off a '50s Michigan 55A front wheel loader. Would I have to find the same exact carburetor to replace this one or could I just match up the size and mounting and I'd be good?
 
 
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