Any McCulloch chainsaw built before the year 2000 is going to be very difficult to find parts for. That is the year that McCulloch went out of business and threw all of the parts in the trash. The Name was sold to a Chinese company. The new saws can have some parts ordered for them but usually those saws are not worth putting a much more than a new spark plug in them if they do not work. They are not well made.
The only possibilities in your case are if you find parts on ebay or if you contact an old-time dealer such as http://www.oldmowerparts.com/
and ask them via email if they have a particular part in stock.
They do have some of the older McCulloch parts in stock.
Try to get the model number of the saw which is in many cases located inside the air filter box.
Sometimes you even have to take the air filter element out of it to find the numbers.
The part that is usually needed is the entire oil pump itself.
You got lucky this time as both of the eager beaver saws use the same oil pump.
And, I found one on ebay for you.
Before you take the saw apart, check the oil hole in the bar and make sure that it is completely open. They like to get plugged with sawdust and will cause the oiler not to work.
Edited by James W on 8/6/2010 at 4:41 AM EST