Chainsaw Mcculloch Mac 335 issue

[Jonny Vee]

all,

Asking on behalf of friend who picked up 2 Mac 335. They seems in very good condition but not starter

I gave him help to clean carburettor and set screw back to 1 1/4 turn. They won`t start unless you out fuel on the cylinder they run for few seconds.

Playing around with carb setting it ended up that only start when L screw is over 2 turn back and H as well 2 turn back. Issue is that when revving to cut and you release the trigger the saw react and keep accelerating like the screw was to lean.

The both react at some thing and I`m lost as always had chainsaw with basis setting at 1 or 1 1/14 turn and behave was okay

Is something out of my knowledge or something else broken like crank seal?

Thanks in advance from Michael

 

[Burnerman]

Crankshaft oil seals are very important on a two stroke, any air ingress here will weaken the mixture significantly.
However, if you can't move the flywheel up and down on its bearings, and there is no oil deposit behind the flywheel you can really rule these out.

Personally I'd replace both of the carburettor diaphragms and their gaskets, and try again from there.....the machine is just not getting enough fuel.
Of course, you may be able to get a replacement carb from Amazon or whatever for about the same price, and I'm finding this is the way to go more often these days.
Point of interest - these machines don't like E10 fuel very much - hence my recommendation of replacement Aspen fuel or similar.
John

 

[Diver Fred]

I'd say the chainsaws were left with fuel in the system, it has dried out leaving behind blocked galleries.

If you are taking the carb's off to service them maybe soaking in fresh neat petrol may clean the galleries. Or John have a suggestion for carb cleaner?