It's an '86 244 with 300,000 miles on the original motor. Compression was fine the last time that I tested it, about six months ago.

I've also tested the battery and the alternator and get "healthy" voltages from both. Even swapped out the battery with a newer one from the truck (F-150) and didn't make a lick of difference.

Here's what happens...turn the key and the starter motor turns slowly. "Chug-chug-chug." After a few complete revolutions of the engine it starts to turn at a normal speed and the engine fires right up. Once it's started the engine sounds and runs like it always has. So the starter is either encountering some resistance or the motor is just getting tired? It's about 7 years old.