Walbro HD carbs

[a. palmer jr.]

I've had a little bad luck rebuilding the Walbro HD type carburetors lately. First one was on a Poulan 3400. Everything went ok until I installed the "O" shaped gasket on the inlet needle side. That was an HDB, if I remember correctly. Anyway, two of those gaskets were in the kit and I guessed the wrong one first and it ran terrible rich. The next one, today, was an HDC on a Homelite XL2. There were also two gaskets in the kit but neither looked like the one I took off. Well, it ran really rich with the one I chose. I got in my spares and found one that looked different than the others and am going to try it tomorrow. I hate it when they make the kits to fit multiple carb. applications.

 

[Roanoker494]

I've had a little bad luck rebuilding the Walbro HD type carburetors lately. First one was on a Poulan 3400. Everything went ok until I installed the "O" shaped gasket on the inlet needle side. That was an HDB, if I remember correctly. Anyway, two of those gaskets were in the kit and I guessed the wrong one first and it ran terrible rich. The next one, today, was an HDC on a Homelite XL2. There were also two gaskets in the kit but neither looked like the one I took off. Well, it ran really rich with the one I chose. I got in my spares and found one that looked different than the others and am going to try it tomorrow. I hate it when they make the kits to fit multiple carb. applications.

I would not think that gasket would make it run rich, unless it is being installed on the wrong side of the diaphragm. I could be wrong though.

Edit:
Never mind.......... I had the installation backwards in my head.......

I have also bought kits with several different gaskets for that side, so far I have always gotten lucky with the one I choose.

 

[a. palmer jr.]

I would not think that gasket would make it run rich, unless it is being installed on the wrong side of the diaphragm. I could be wrong though.

Edit:
Never mind.......... I had the installation backwards in my head.......

I have also bought kits with several different gaskets for that side, so far I have always gotten lucky with the one I choose.

I also lowered the needle lever when I changed the gaskets but not very much.

 

[redunshee]

For the HDB I assume you're referring to the circular gasket that surrounds the metering lever and needle. I assume you tossed the old one so you couldn't compare them? I always hang on to the old parts to compare cause many kits provide extra parts to cover differant carb models. I also change the metering needle and lever even if the old one looks okay.
Bob

 

[a. palmer jr.]

For the HDB I assume you're referring to the circular gasket that surrounds the metering lever and needle. I assume you tossed the old one so you couldn't compare them? I always hang on to the old parts to compare cause many kits provide extra parts to cover differant carb models. I also change the metering needle and lever even if the old one looks okay.
Bob

Actually, I did save the old one, it didn't compare to either one in the kit. The kit number wasn't the one I looked up online but it was close to the number so I thought the counter man gave me one that would work. He's had a lot of experience with these and hasn't steered me wrong in the past. This is one of the carbs that only has one adjustment, the "L" screw. I did change the needle but the lever wasn't included in this kit. Looks like to change the lever you'd have to change the round plate also, the pin is pressed into the opening in the round plate but probably could be taken out. Mine looked pretty good so I left it alone.

 

[a. palmer jr.]

I got me a handful of the O shaped gaskets and was gonna keep changing them until I got the right one, when I finally got the saw running and noticed the saw was still running rich...with oil! It appears the crankcase is full of bar oil. Now I have to figure out if I have the (new) oil lines misrouted or if the diaphragm for the oil pump is kaput. I wonder if I can bypass that diaphragm pump because some of those little Homelites don't have it, they just have a line from the engine to the tank then from tank to the oiler outlet at the bar. This is an awfully nice looking saw or I probably wouldn't put this much effort into it..

 

[w8ye]

The oiler has been the problem all along?

 

[a. palmer jr.]

The oiler has been the problem all along?

I think I had two problems, the carb definitely needed rebuilt, judging from the looks of the insides of it, but I think it was my own stupidity when I put the new lines on the oiler I got them switched. I knew better, I've done several of these saws. The kicker was, today after I put it all together and started it up it ran good for awhile then all of a sudden it started sounding funny then ran away with itself, I remembered I'd set the idle all the way up so it wouldn't die and it died anyway and wouldn't start so I adjusted the carb again and then it hit me to check the fuel...it was out of gas! I've had a rough time with this saw, hope I don't get any more of these for a while!

Two reasons the carb needed gone over, it was filthy and when I got inside it had the inlet needle lever pulled way up past the surface you check it by. I know it would have never ran, in fact it didn't run. I tried it several times before I tore into it.