Bought 1991, 75,000 original miles,..
 

Hi, I just purchased a 1991 miata with 75,000 original miles, it seems to be in very nice condition but I am wondering about the things I should check....It runs o.k. shifts o.k. but how do I check if the timing belt has been replaced and other things. I am taking it to my garage, check and change all the fluids etc. any other things I should be concerned about? thanks for any help.:)

No history from the previous owner? Definitely have all the fluids changed out. Check the belts that are visible, if they are old and cracked and you cannot get info about a timing belt change, I would go ahead and do it. If the visible belts are pretty new, hold off on the TB change, but do one before 150K if it doesn't fail before then. The worst that can happen is the car just stops if the TB breaks. Since it is a non-interference motor all you will really need is AAA to get you to a repair place.

Watch the bottom hub while the engine is running. If you see any wobble, have the nose of the crank fixed right away and do the TB/water pump at the same time. If it is a short nose crank, be sure of your mechanic.

Not much info on what has been done by other owners, I ran a carfax check, the mileage is verified, it has 5 previous owners, but way to contact them. The interior is in excellent condition, everything works and the body is nice. It did have a minor accident in 2005 but nothing serious. (front bumper). It has new tires and wheels. I will try to post a picture. Anyway thanks for your reply, I will be working on it this spring.

Yes, the 1991 will likely be the short-nosed crankshaft and will need to be monitored for crank pulley wobble. If left unchecked it can destroy your crankshaft and require a major overhaul. If it doesn't wobble, they are fine engines and will last forever.