Carburetor Expert's

ELT

Active Member
#1
I'm trying to put together an original tecumseh carburetor for my rebuilt hs50. I have 3 carburetors that I've cleaned and adjusted but they aren't right. Two of them will idle perfectly but are way to rich when I open the throttle. I can close the load needle and it improves but it's still to rich. The other carburetor will run on the high speed side but won't idle
I've used lots of carburetor cleaner and air, I do get flow all the way through the idle side. The mystery pin rattles in the carburetor and I have a good o-ring on the idle adjustment screw. I'm setting the float levels using the tecumseh level gauge.
 
#2
The ones that run rich on the main system, possibly the main air bleed or emulsion tube is blocked or restricted. This is where the fuel mixes with air to form an emulsion. Not enough air and it will pull more fuel from the bowl.
 
#3
When you cleaned them, what method did you use? (e.g., spray carb cleaner, carb soaking solution, ultrasonic machine, or ?) Also, did you remove all of the welch plugs during your cleaning process?
Michael
 

ELT

Active Member
#4
The ones that run rich on the main system, possibly the main air bleed or emulsion tube is blocked or restricted. This is where the fuel mixes with air to form an emulsion. Not enough air and it will pull more fuel from the bowl.
I seem to be getting a good flow of carburetor cleaner to flow through that air passage and down by main nozzle
 

mustangfrank

Well-Known Member
#6
The one that won't idle...you said you're getting good flow through the idle side, the two smallest holes in the venturi/bore (closest to the throttle plate) are flowing? I can usually get those clear with just the smallest wire on the tool (tip bent 90 degrees) if I'm running low on welch plugs. And gotta ask, you had the carb upright when you put the idle screw back in, correct?
 

ELT

Active Member
#8
The one that won't idle...you said you're getting good flow through the idle side, the two smallest holes in the venturi/bore (closest to the throttle plate) are flowing? I can usually get those clear with just the smallest wire on the tool (tip bent 90 degrees) if I'm running low on welch plugs. And gotta ask, you had the carb upright when you put the idle screw back in, correct?
I have the 2 idle passages cleaned and can see carburetor cleaner spray out of them so I don't think they are a problem. I didn't pay attention to thr carburetor position when I put in the idle mix screw. I will pull it out and make sure nothing is damaged and reinstall it with the carburetor on the motor.
 

ELT

Active Member
#9
I decided to experiment on a junk carburetor I had laying arount. I enlarged the lower end of the emulsion tube and tapped it to 4-40 thread. I pulled the tube with a machine screw and nut. I only enlarged the botom of the tube not the business end.
 

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desert rat

Well-Known Member
#11
I decided to experiment on a junk carburetor I had laying arount. I enlarged the lower end of the emulsion tube and tapped it to 4-40 thread. I pulled the tube with a machine screw and nut. I only enlarged the botom of the tube not the business end.
o_O
 

old shed finds

Well-Known Member
#12
I'm trying to put together an original tecumseh carburetor for my rebuilt hs50. I have 3 carburetors that I've cleaned and adjusted but they aren't right. Two of them will idle perfectly but are way to rich when I open the throttle. I can close the load needle and it improves but it's still to rich. The other carburetor will run on the high speed side but won't idle
I've used lots of carburetor cleaner and air, I do get flow all the way through the idle side. The mystery pin rattles in the carburetor and I have a good o-ring on the idle adjustment screw. I'm setting the float levels using the tecumseh level gauge.
If I had a dollar for Everytime I tried to get these starting and running good I'd be a millionaire! I tried eBay carburetor and still haven't run correctly..
 
#18
I just put a China Tecumseh replacement on my Powell and it works just fine. I have a HS50 with a chikuni that also runs fine but I am about to try a 21mm PWK on it as I feel the chikuni is a bit big for it.
 
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