I started rebuilding a Walbro SDC carb today.There really wasn't much to it till I got to the Welch plugs.Is it necessary to remove them when rebuilding a carb,if so,why?Also,how do you get the old plugs out?Another thing,what are those little snap rings for?
I thought that the metering spring went in & stayed in relatively easy.I did go around the welch plugs with the tip of an ice pick,there was a lot of stringy crap there,I'm glad I did that.I'll have my son giver me a hand later on that spring.
I don't think it was sealer Tim,it had no consistency to it,it was more like dust,it came off too easy.A sealer would've been more sticky.Kinda hard to describe.It came off way too easy too.I just lightly scratched it.I didn't want that crap going into the carb.
A real nice looking SXLAO.I'll get some pics up when I'm finished tomorrow (hopefully).My son got the metering spring in under that tit.I just need to put the cover back on the carb & install in the saw.I should probably change the fuel filter too.
I put the cover back on this morning while having coffee.Now it's on to installing back in the saw to see if it'll run.The fuel line looks like it's already been replaced because it's not the black line that was in originally.I noticed a wrinkle in the old metering diaphragm.I'm going to look at the fuel filter as well.
Post by jerseyhighlander on Mar 13, 2018 17:35:55 GMT -5
With everyone else on the Welch plugs, I do them if I really need to, like if the carb had bad varnish or corrosion or if I just feel like making sure and not having to go back into it. More often than not, nothing to find in there. Smaller ones are usually just access to circuit or jet holes that you can get from the other end. Bigger ones usually have the fine mesh screen, more often than not clean but even when they caught some junk, they did their job and kept it from getting into the works.
To remove them, you punch a hole through the center at a low angle. I use a nail set that I ground to a steep chisel tip. They either pop up from there or give you purchase to pry them up.
The little snap ring is for a small diameter brass screen, usually the opposite side of the metering needle or under one of the Welch plugs. As long as they are intact and clean I never replace them.
The white stuff is a sealant from when the plugs were installed. Think of it like caulking squeezeout. Have seen it on several carbs.
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Post by lesorubcheek on Mar 13, 2018 18:51:18 GMT -5
Count me also. I can't remember the last time I removed a welch plug on a carb. Usually carb cleaner does the trick, and if not, the ultrasonic is for the second round. One little tip from AS is to use some nail polish around a new plug to help it seal. It's supposed to be resistant to gasoline. Not sure about alcohol, so others may jump in to add additional advice.