okay so i have a friend who is buying an fc n/a that has 130831 mils on it...we are wondering should we rebuild the motor??

 

If it runs and does not smoke excessively, you should start putting away money for an eventual rebuild. Don't go tearing it apart on speculation that it may need a rebuild soon. After 130K you are on borrowed time, but why not take full advantage of it? You might get to 200K, if you're lucky. No matter how much money you have already set aside for a rebuild, saving up more by waiting will benefit you. The more new parts you are able to use, the better your prospects of getting another 130K out of the rebuild.

Quick economics lesson: Apex seals, side seals, corner seals, water seals, oil control o-rings and all the springs will cost about $1,000 from Mazda. Rotor housings would cost about another $1,000. Obviously, this presumes everything else is in spec. While most people cheap out on their rebuild and re-use a lot of parts, the more money you spend on these things, the better off you are. It's an investment. Sure, if you don't plan to keep the car very long, re-using as many parts as possible is probably the way to go. But, it will invariably cost you more to rebuild the motor twice cheaply than do it once right, so if you are in it for the long-haul, invest the money up front. Just my $0.02.

 

If you can afford it, buy new apex seals, and rotor housings. You'll make more power, and it'll start alot easier when its a fresh rebuild.

As for motor longevity, my first 2nd gen had 160k miles on it, when I had the motor rebuilt, and it was still running fine. And my 2nd second gen, died at 133k miles do to the "driven like a little old lady" owner.

When its time for a rebuild, I highly recomend Pineapple Racing. CJ