Hi, it's been long time since I've been in here.
I have a 90 miata, with a 92 engine (crankshaft failure) that I just replaced the alternator and belt back in December. The temperature would go up when ever I drove above 4000 rpm for more than a few seconds. I assumed that the belt was slipping, so I tightened it around a week ago. This was after checking the tension about a 1000 miles after original installation and tightening it then. Later that day I'm driving along and the belt snapped. I assumed that it was a defective belt, becuase it seemed to stretch way too much. I limped my baby to Sears (1 mi away?) where I bought a belt and installed it. (Sears wanted way too much to install a belt, and I'm pretty well broke so I couldn't afford to pay them if I thought it was reasonable right now anyway.) When I got home, i checked the tension, cause I did it in their parking lot as fast as I could. Everything seemed fine. So today, I'm driving to work (34 mi one way) and I have the same problem happen again. Any thoughts? This isn't the first time that I've installed a belt, but it is the first time I've had a problem like this. The odd thing is that this only seems to happen at highway speeds, it does not happen if I drive 40 mph in second gear.
Thanks, Karl & Maverik,
90 Red.