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McCullouh chain saw

jlm's Avatar
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01-07-04, 11:44 AM   #1  
McCullouh chain saw

I had the pleasure of getting a Mac 35 saw to repair that someone else took apart. My question is in the connections of the fuel line thru a primer.
There are three hoses: 1 goes to the fuel filter in the tank, 1 is in the fuel tank but just enough to close the hole and there is another line which I assume goes to the input side of the carb.
There is a rubber bulb that fills with gas when you push it in.
I assume the fuel filter line goes to the primer and the output of the primer goes to the carb. and the third line from the opposite side of the carb goes back to the tank? Is this right?
Is there a input and output side to the primer? If so how do I determine?

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01-07-04, 12:43 PM   #2  
Yes the primer does have an input and output side. To figure out what side is the output, just shoot a shot of something like wd-40 into each side and push the primer bulb, it will only shoot out on one side. One fuel line does come from the tank to the carb, then another fuel line goes from the carb back to the primer. Then the last one goes from the primer to the tank. If you hook the supply and return fuel lines to the primer wrong, then it will never start.

Last edited by mower17; 01-08-04 at 04:46 AM.
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01-07-04, 08:45 PM   #3  
Hello jlm! Find the suction port on the primer. It should be connected to the short hose going to the carb. The line with the fuel filter on the end of it in the tank should be connected to the supply port on the carburetor. The return line also goes into the tank, and has no filter on the end of it. It should connect to the pressure port on the primer. What it does is draw fuel thorugh the carb, and pump it into the tank, to completely fill the carb with fuel, and pressurize the tank a little with whatever air gets pumped into it when priming.

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01-08-04, 04:19 AM   #4  
Thanks I think I understand now. The fuel lines were gone when I got the machine so that's why I had nothing to reference.
So if I understand, The line with the fuel filter goes to the needle and seat side of the carb. The line from the opposite side of the carb (bottom side) goes to the suction side of the primer and the last line goes to the tank as a return for the gas drawn in thru the carb by the primer. Sounds logical to me. Thanks, I'll let you know how it works after this weekend.

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01-19-04, 04:24 AM   #5  
Just an update on this saw. I got the fuel lines set up and the machine runs fine until it gets hot, then it guits, no spark, I've ordered a new coil and hope this will take care of everything.
It ran great when it was running!
Thanks for the help.

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