Chainsaw Repair

I recently "rescued" a Poulan 25 DA chainsaw from the scrap heap. Cosmetically speaking it's in very nice condition. I put some fresh fuel in it and tried to start it. No luck. So I put in a new fuel filter, fuel line, spark plug and an air filter. It ran pretty well after that, but it was pretty hard to start. So I cleaned the carburetor and put in new needle and gaskets. It's still hard to start when its cold. I think this is mainly due to the fuel draining back and leaving the carburetor dry. So that's problem one.

Secondly, the chain oil does not seem to be working. It's not oiling automatically and the manual pumping button seems frozen.

Thirdly, what gas/oil blend should I be running? I think originally Poulan specified 32 to 1. The mix I keep on hand is a more standard 50 to 1.

And finally, there is the matter of the quarter inch pitch chain. The saw could probably use a new bar pretty soon. I'm finding that it's pretty hard to locate bars and chains in that pitch, except for specialty items for wood carving. I'm thinking about changing the sprocket so I can run three-eighths pitch. Is it possible? If so where should I be looking the right parts? For instance, would the clutch drum/sprocket from the Poulan S25DA be a straight swap?

It seems like a lot of work and expense for saw like this, but I'm just going to take a little at a time see where it takes me. It's already served me to do some tree trimming around the property and it cuts pretty nicely.

Thanks. I like you answer because I am well disposed towards fixing it just because it pleases me, even if it doesn't make economic sense.

I'm not sure what you mean by "hard-nosed" bar though. Perhaps you are referring to a bar without a roller sprocket in the nose. In any case, the 1/4" pitch chain on the saw now is pretty sharp, so no hurry to change it. The hard starting problem this is a thing I need to address next. I did put a new fuel line in it already. I'm pretty sure the problem lies with the needle in the carburetor. The answer may be as simple as me learning how to properly adjust the tab that pushes the needle.

In the meantime, I have learned that the clutch drum/sprocket for 3/8" chain is readily available and easy to swap. Once that is done a good selection of chains and bars becomes available.