Logo
FULL SITE MENU

Getting my 20 running again!!

Mystery solved. It looked like a fixed bushing but after a sonic bath some dismantling lubricant and managing to get pressure from a wrench (one jaw on the end of the slow tube and one jaw on the outside end of the main tube that houses both jets) it squeezed out as a pair. The slow jet needs replacing but I am back in business. Thanks very much for your help. For anyone reading, the slow jet only comes back out of the main emulsion tube after you remove them both from the carb body as a pair. It wont pass all the way through the main emulsion tube.
 
So, you're saying that the top of the main emulsion tube snapped off and was stuck in the hole??
If so, that's a new one for me.
 
No. Not saying that. Just that what l had previously described as a sleeve or bushing, was the inboard end of the main emulsion tube projecting up into the carb throat. It was stuck hard initially (hence my question whether it was fixed) but after a sonic clean and some dismantling oil it pressed out bringing the small tube with it as a pair. Once out they can be separated (as you already know…). After a further clean they now slot in and out easily.
 
Ok, that makes sense.
Glad you finally figured that out.

That main emulsion tube typically falls out on it's own when the plug holding it in is removed.

I think that, because you said that the screwdriver slot in the plug is deformed, it was way overtigtened and the main emulsion tube was jammed in there and also the jet set was cracked. As a result, I would consider replacing both tubes and the plug as there has obviously been distortion/damage done to all three.

You say the accelerator pump delivery tube and orifice are clear. I am interested in how you went about determining that and if you tested for the stream of fluid from the orifice. Did you use carb spray, with the straw, to "backflush" the orifice?

If this carb sat a long time with old gas in the float chamber, I would be pretty worried that the primary fuel jet could be plugged. Not to be confused with the main jet, the primary jet is unique to that carburetor and plugs easily because it is so small. Getting it clear can be difficult because it's up inside the brass tube that's in the main body on the opposite side from the SE dip tube location. It's next to the accelerator pump piston plunger rod and both can be seen when the float chamber is off.

If the primary jet is plugged, the engine will start and run but will never reach full power.
I have never found a specification for the size of that jet. I only know that when it will pass carb spray, the engine will reach full rpm.

The primary jet nor the tube are removable or replaceable.
 
Back
Top