Mcculloch pro mac 610 chainsaw

[565woot]

my old mcculloch pro mac 610 is down think it is carb has zama c2s, it will start and idle just has no power, checked compression at 120, so ruled that out, seem like not getting enough fuel, any help would be greatly appreciated.

 

[farmguywithasaw]

my old mcculloch pro mac 610 is down think it is carb has zama c2s, it will start and idle just has no power, checked compression at 120, so ruled that out, seem like not getting enough fuel, any help would be greatly appreciated.

Plugged exhaust. 120 psi is on the lower end of ok. Might not be a bad idea to check for scoring

 

[565woot]

Yeah took exhaust off ,surprised how clean it was, yes I seen some scratches on piston , saw has been amazing for 35 years and still strong till aweek ago.

 

[farmguywithasaw]

Well I would say it’s time to freshen up the carb, fuel line, and filter. Also check and make sure the tank vent is working and not plugged. I believe they are in the cap on those. I would check for air leaks as well

 

[565woot]

Yeah if 120 psi is low, that's probably the problem, when you go wide open it just doesn't Rev up and looks like it is blowing fuel out of carb , blow by? I just thought it was a carb problem,

 

[farmguywithasaw]

Yeah if 120 psi is low, that's probably the problem, when you go wide open it just doesn't Rev up and looks like it is blowing fuel out of carb , blow by? I just thought it was a carb problem,

Yeah that is an indication. Blow by can leave a brownish stain between the rings. Could just re-ring it might be all it needs. Scoring can be in areas that are hard to see through the exhaust pull the carb and look through there

 

[565woot]

Yeah scratches there to, changed fuel line ,filter, any adjustments on carb don't change running.

 

[heimannm]

Older models had thick rings, the rings are still readily available. Later models (after November 1984...) had thin rings and they are difficult to source. There are some thin ring pistons out there, and Little Red Barn offers a replacement but you need to change the wrist pin bearings for OEM type and reuse the original wrist pin if you go LRB. I think the LRB pistons are one ring vs 2 on the originals.

Mark

 

[Mnmacguy]

checked compression at 120

My 610's check out at about 110-120 and run excellent. The spark arrestor screen on the muffler getting plugged with carbon is a common problem with these saws.

Sent from my moto g(7) optimo maxx(XT1955DL) using Tapatalk

 

[565woot]

I have had exhaust off , carb off disassembled, new fuel filter and line, new plug still will not run wide open. It will idle just fine , sure acts like it's in the carb ?

 

[heimannm]

What color is the electronic ignition coil? The brown ones were very reliable but the later grey or white ones had problems from time to time. I had a local guy with one that went bad and even allowed the saw to run backwards. Changed the coil and the saw was back in business.

Mark

 

[565woot]

Pretty sure it is Grey, took it off and cleaned it and flywheel, I kinda figured it is 35 yrs old, but with electronics it either works or it doesn't. But I'm probably wrong with that .

 

[565woot]

I was thinking of buying new coil and carb rebuild kit.