Thanks everyone! It has a fuel tank but I don't know how that helps.
Open the filler and sniff. See if you can smell whether it has or had gasoline or diesel in it.
Do research on-line (Google is your friend). For the year of your boat. See if you can find out whether they typically had gasoline or diesel engines in them.
There used to be a very active Pearson mailing list hosted by Sailnet that was a terrific
Pearson resource, but I guess they weren't making enough advert revenues off the mailing lists they hosted and they one day just up and pulled the plug w/o warning. Now there are two Pearson mailing lists, one on Yahoo! and one on Google, both of them together not having as much traffic as the Sailnet one used to have, I'm told. But you can look for them, join them, and ask there. The Pearson activity on Sailnet's web forums, which is where I imagine Sailnet hoped to drive everybody, isn't even merely a shadow of the old Pearson mailing list activity.
Yes I did get the boat cheap.
Here's the thing about "cheap" boats: They more-often-than-not aren't. Rarely does somebody just up and "give away" a good boat that's in good repair.
You should probably pop for having a qualified
sailing yacht surveyor give her a good going-over before you're out one day in a stiff blow and find yourself with your mast, rigging, etc. down around your ears, or worse.