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Discussion Starter · #1 ·
Hi,

I was given this chain saw that did not run. The previous owner said that it probably needed a carburetor rebuild or cleaning. So, I removed the carburetor. I noticed that the gasoline hose just fell apart when I took the carburetor out. See the photo. Could that have been the problem? The carburetor from as far in as I could see it looks clean.

Also, are there any good videos showing how to rebuild the carburetor if need be? Would buying a replacement be a better idea?

What is the proper gap for the plug?

Thanks.
P4210057.JPG
P4210058.JPG
 

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Discussion Starter · #2 ·
I found that the plug gap should be .025" What are the high and low settings for the needle valves?
 

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A neighbor saw an old XL like that at the landfill and brought it to me. I put some new fuel line on it, poured some gas in it, and it started right up.

Replace the all the fuel line and pump lines, pour a drop or two of gas down the carb throat to prime it up some, and I bet it'll run. It probably doesn't need a carb rebuild.

I did have to put a new chain on it, but it has since cut a lot of wood for me. Those old XL's are bulletproof. REMEMBER! IT DOESN'T HAVE AN AUTOMATIC OILER. YOU HAVE TO KEEP THE CHAIN OILED MANUALLY!
 

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Discussion Starter · #7 ·
A neighbor saw an old XL like that at the landfill and brought it to me. I put some new fuel line on it, poured some gas in it, and it started right up.

Replace the all the fuel line and pump lines, pour a drop or two of gas down the carb throat to prime it up some, and I bet it'll run. It probably doesn't need a carb rebuild.

I did have to put a new chain on it, but it has since cut a lot of wood for me. Those old XL's are bulletproof. REMEMBER! IT DOESN'T HAVE AN AUTOMATIC OILER. YOU HAVE TO KEEP THE CHAIN OILED MANUALLY!
Motormonkey, I put the new gas hose in from the carburetor to the gas tank. I used the whoIe 12", stuffing the excess into the gas tank. I hope that was alright. I did not put the gas in the carburetor throat though and it did not start. I had trouble bolting the carburetor back in. Maybe there is a gap.

You mentioned a pump. I did not see one and therefore could not replace the hose.

Does the cylinder create a vacuum to get the gas from the fuel tank into the carburetor?
 

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There is a diaphragm pump built into the carburetor that pumps fuel from the tank to the carb. Crankcase pressure pulses operate it. On some saws there is a separate line from the crankcase to the carb to operate this pump. On other saws, there is a port built into the carb mounting flanges.

If there is no fuel in the fuel system, it can take a LOT of pulls on the starter rope to get fuel pumped from the fuel tank into the carburetor. That is why I suggested pouring a few drops of fuel into the carb to get it to momentarily run enough to start fuel to pumping. You may have to do this a couple of times.

As far as installing the carburetor, I have no idea what sort of problem you're having. If there is a gap, it could be a damaged gasket, some foreign object, or it could just be assembled incorrectly. In any case, you'll have to address that before trying to start it. Exploded parts diagrams are available on the web that could help you.
 

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Discussion Starter · #9 ·
There is a diaphragm pump built into the carburetor that pumps fuel from the tank to the carb. Crankcase pressure pulses operate it. On some saws there is a separate line from the crankcase to the carb to operate this pump. On other saws, there is a port built into the carb mounting flanges.

If there is no fuel in the fuel system, it can take a LOT of pulls on the starter rope to get fuel pumped from the fuel tank into the carburetor. That is why I suggested pouring a few drops of fuel into the carb to get it to momentarily run enough to start fuel to pumping. You may have to do this a couple of times.

As far as installing the carburetor, I have no idea what sort of problem you're having. If there is a gap, it could be a damaged gasket, some foreign object, or it could just be assembled incorrectly. In any case, you'll have to address that before trying to start it. Exploded parts diagrams are available on the web that could help you.
I took the carburetor off, shortened the gas hose and reassembled it. It went smoothly. As per Motormonkey's advice, I put some gasoline in the carburetor. It did run for a short time using the gas that I put in the carburetor. I could not see any gasoline in the gas hose. Does anyone have any further advice? How to we get the gas to go from the tank into the carburetor?
 

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place a vac gauge on the fuel tank inlet.
see if you are getting a vac pulse when it is turned over...

did you find the fuel pump diaphragm and replace it?
 

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The flat cover plate with four screws is the cover for the diaphragm fuel pump. There is a flexible plastic diaphragm under that cover. If it is cracked or inflexible or has any holes in it, that could be the cause of your problems. Disassemble it carefully and inspect it. Carb rebuild kits are available for not a lot of cash, and a replacement diaphragm should be part of the kit.

Something I noticed from your pictures. Cleanliness is vital to properly repairing these things. A bit of sawdust or crud on a gasket surface can cause an air leak... and all manners of grief.
 

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that might be close...
make sure the gaskets are right..
they use gasket holes on some models for the impulse for the fuel pump.
 
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