McCulloch 4000 chainsaw parts diagram and tuning information

Here’s a scanned parts diagram for an old McCulloch 4000 chainsaw, made in Italy, with a Tillotson carb. This is a little different than the ‘4000 California’ model.

Click for full size

The operator manual shared for the 3500/4000 series doesn’t have anything too interesting, but here’s the key information:

Fuel Mixture:

  • McCulloch oil 40:1
  • SAE40 2t 20:1

Chain Oil:

  • SAE 30 motor oil, or McCulloch chain oil no.201349
  • Refill the oil tank each time the saw is refueled

Tuning specs:

  • Spark plug gap: .5-.6 mm
  • Low speed base tune: 1 full turn out from closed
  • High speed base tune: 1 full turn out from closed

Service specs:

  • Chain tooth angle: 35 degrees
  • Every 10 hours: Remove sparkplug, clean and adjust gap
  • Every 20 hours: Replace sparkplug
  • Once a year: Contact your dealer for a full service (no explanation of what this includes)

There are 2 part numbers on the Toyota diagram!

If there are 2 or more part numbers for one part on your Toyota diagram, marked with a ※ (the x with dots means reference mark), look for a legend to explain further. Sometimes it’s on the next page. Different trim levels and equipment specification are fitted with different parts, usually this is made clear in the legend or part name.

However, sometimes you find something like this:


… Without an accompanying explanation. At first I thought it was a range of chassis numbers, but they’re actually date codes in the form YYMM. I don’t know how Toyota aligns the change over, so ask your parts guy if you need to.

It took me a little while to figure out, so now you know.