McCulloch PM 610 fuel coming out exhaust and other places will not start!

[Thelogdog]

I got a McCulloch PM 610 I believe it’s the power Mac model for super cheap not running the other day. I got the old gas out of cleaned out the tank a little with some good fuel then filled it a little slapped a new plug in there real quick and tried to start her and it shot fuel out of a couple different places like 4th and 5th pull. Out the exhaust looks like a little is on the flywheel cover. First time working on a McCulloch! I’m a rookie saw mechanic but I have learned a decent bit! The fuel lines look pretty good like they have been replaced at some point. Where should I start?! Any knowledge or info on the saw I need to know would be much appreciated!

 

[Gaspowered]

First thing I would check is the carburetor, If it had old gas in the tank, that means that there's old gas in the carb. Diaphragm carburetors are allergic to old gas, the nasty-smelling orange varnish that we call old fuel will soak into the diaphragms over time which will cause them to become very stiff and inoperable. The "metering diaphragm" (this controls how much fuel is drawn into the carburetor) is basically your float bowl on a diaphragm carb. If that diaphragm is hardened up, it's probably sticking in the open position, which is causing raw fuel to flow past the needle valve and flood the intake and combustion chamber with fuel, which is coming out of the muffler. Kind of like a float carb, varnish can "glue" the float to the bottom of the float bowl, causing it to flood. Cranking it over just draws more and more fuel without regulating it. I'd say pull the carburetor off, clean it, and rebuild it. Carb kits are very cheap and easy to get. Do the fuel line too, old gas shows no mercy on rubber parts, especially fuel lines. McCulloch saws are awesome saws, I have a lot of them, and they are good runners if you take care of them. They're also good starter saws if you just learning the basics. (Depends on the model.) Your PM (stands for Power Mac) was the big saw that was part of the Power Mac line, it's about 60cc. The smaller saws in the line were called 310, 320, etc. The 610 was made from 1978 to 1985. Like I said before, you need to rebuild you carb, and this saw will either have a Tillotson model HK, a Walbro model HDB, or a Zama model C2. All of the carb kits for these are available.

 

[Woodslasher]

@pioneerguy600 can you move this, please?

 

[farmguywithasaw]

Fuel line could be leaking as well check for spark too. Mine needed a grommet where the line went into the tank

 

[RED-85-Z51]

Id rebuild the carb first...then go from there. You can almost count in having to break it down to replace the oiler hose

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[Thelogdog]

You guys are awesome! I really appreciate the knowledge! I’m still learning but you guys helped me out a lot. So I’m gonna start with the carb rebuild. When installing the rebuild kit do I have to set the needle? And I was wondering is the OEM fuel line the black line or is it the clear line? I also read something about a grommet between the side of the tank and the side of the box underneath the air filter that I should be worried about? Thank you guys again!!

 

[RED-85-Z51]

You guys are awesome! I really appreciate the knowledge! I’m still learning but you guys helped me out a lot. So I’m gonna start with the carb rebuild. When installing the rebuild kit do I have to set the needle? And I was wondering is the OEM fuel line the black line or is it the clear line? I also read something about a grommet between the side of the tank and the side of the box underneath the air filter that I should be worried about? Thank you guys again!!

Yes but if its the Walbro HDB carb the needle needs to be flush with the gasket mounting surface using a flat object laid across it.

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[djones]

While you're at it, check for spark. The 610 has a tendency to lose spark from the coil. If it's good then you're fine, if not you'll need a new coil or a good old one. If you can't find one for a 610 then any standard 10 series coil will work if you put a longer plug wire on it. I have done this to a few of them for myself and some customers.