I have a Magic Chef oven that has been converted to propane. When I turn the termostat knob to 350 the igniter glows bright and after about 15 second the burner ignites. It stays lit for about 3 or 4 minutes then shuts off. It stays off for about 30 seconds and relights. It stays lit the second time for about 3 or 4 minutes then goes out for good. The temperature only gets up to about 200 and drops after the burner goes out the last ime. The ignitor glows bright the entire time.
Is this indicative of a termostat malfunction or some other problem? What parts might I need to make my wife happy again?

Thanks,

Ron