Techumsa Carb Tech Ques?

Hi all, newbie here. I only work on my junk and friends stuff that quits. My latest thing is that I have three Techumseys backed up for the same carb problem.

The cause is after letting the gas sit in the carb for three years, I hear "Dave it won't run anymore, can you help?"

I can get the carbs cleaned and soaked and the motors will fire up and run ok but always need a little choke - theere is some gunge in there.

Is there a sspecial tool or procedure to get the plastic tube out that is held in with the two O rings? I am betting that inside there is the major problem. Main Jets at bottom of carb are clean.

Also, to get it back perfect is is necessary to knock out the little welch plug and get into that area?

I think I will be able to get the parts.

Looking for experience and appreciate any input on this pesky problem. Thanx

 

henryJ
I usually use the flat tip of a screwdriver and push out the plastic main nozzle from the inside of the carb throat down into the float chamber . I can carefully pry out the 2 o-rings that are in there with a dentist pick. As for removing the welsh plugs, if you want to get at all the orifices for cleaning, it would be recommended. The welsh plugs usually come with a kit, if not they can be purchased separately.

snoman

 

Tecumseh does have a tool for this, part number 670377. It will do ALL the procedures related to the newer, fixed jet carbs. Personally, if you're not familiar with the welch plugs (what's behind each one), I'd stay away as you could do more harm than good if you don't remove them correctly. Soaking a blowing out with compressed air will suffice.

 

Thanks for the info. I picked up the tool and some of those $1.75 O rings among other things.

 

Well I got the Welch plugs out of my Tecumseh diaphragm-type carburetor. The service manual suggested removing them and it's fortunate I did because, even though I thought I'd blown everything out before I removed them. a bunch more gunk came out after I sprayed carburetor cleaner in the holes under the plugs (this carburetor was really a sad mess). I've read quite a lot on this forum and other places about the Welch plugs and still have a question. Does anyone know from experience the best and safest way to install them?

 

Don't hit them in the center until the plug is fully seated in the bore. You might have to tap it in around the edges a little with a small punch. Once it's in place, tap it in the center a bit. Not too hard, or it will go too far and not be useable. You want to hit it enough to spread (it's concave, like a bowl, and the bottom of this "bowl is what should be facing out. When you hit it in the center, it spreads the diameter of the plug). When it spreads, it pushes tightly against the sealing edges. If you hit it too hard, it will go flat or convex and be useless. Use a small short dowel or flat large pin punch. Don't use anything pointed or small enough to make a dimple in it. Some people like to put a little locktite around the edges of them. I don't.

 

I've heard people insist on using loctite too... and I've tried removing a plug that had that done to it. I use clear nail polish, it seals but doesn't make removing the plug a chore later down the road.

 

Here, here on the nail polish, I too use this method.

 

Thanks for your help. I installed them using a punch the same diameter as the plugs and, fortunately, they went in like a charm. I just pushed them into the hole until they were fully seated, placed the punch and whacked with a regular carpenter's hammer. The trick was using the right amount of force on the hammer and after being lucky on the first one, the rest were easy. There were three plugs in two sizes. I think if I had to do it over though, I would have flattened one on the work bench just to see how much force was needed, rather than doing the first one in the carb. Again. I appreciate the assistance. I also coated around the oustide of each plug with clear nail polish after they were installed.

 

Glad it went nice and smooth for ya

 

I set my plugs using a socket slightly smaller than the plug to tap only the perimiter. Then used the flat end of my 3/8 extention to seat them.