Chainsaw Repair

I had no experience with chain saws until inheriting my father's Montgomery Ward TMY 24062B three years ago, which I am informed is really a McCulloch Mini Mac 30, 10 incher.  I went to Home Depot and the guy got it going, and I used it several times until the chain wore out.  I could not find a new one, so I put it down.  Otherwise, it functioned fine.

I finally found a new chain a month ago, the Oregon S39.  When I put the new chain on, the cord became incredibly hard to pull.  I opened it up a little and turned the hex screw to the drum a little, but it didn't seem to help much.  I came across some advice that you should take out the spark plug, (new three years ago and little used), and see how it goes.  The cord moved much, much easier.  The spark plug was all oiled up, the gap was filled with oil.  When I put the spark plug back in, the cord went back to being almost impossible to pull.

I don't have the manual for either the Wards TMY24062B or the McCulloch Mini Mac 10, just a parts list I came across online.  So I filled the oil reservoir to the top before I changed the chain. I don't know that is too much .  SAE 30 weight oil.

The unit was running great 3 years ago, for the several cutting sessions I used it for.

Where do I go from here?

Thanks for the reply.  I put the SAE 30 in the compartment labelled "Chain Oil" and TruFuel 50:1 in the compartment labelled "Fuel Mix".  With this setup, three years ago I had several successful cutting sessions until I needed a new chain, which I couldn't locate until now.  The 50:1 fuel was recommended by the guy at Home Depot, but he admitted that it was his best guess-the saw was manufactured well before he was born.  But his advice got the saw functioning quite well for several sessions.

What's next?  I read around about something called "de-carbonizing".  My only experience with that term was in the repair book for an MGB some years ago, they recommended taking out the spark plug of the suspect cylinder, dropping a ball bearing in there and running the car for a little bit to break up the carbon.  Don't think it works on single cylinder units, though.

What do I try now?

I would not run 50-1 in that saw.   40-1 is about as light as I would go.

Thanks Al I did not know about the oilers on those.

When I was at benton farm equipment, we'd give them away with the purchase of a new 10 10, titan model or bigger. We rarely sold them separately.