OK, I got my ST-15 going today its got one tank through is at idle. I got it running while I had my finger on the brake (forgot to mess with the throttle trim) and it was running pretty good. It cut out a few times but it started right back up. Then one time it cut out and locked the whole engine up. I removed the glow plug because I thought I had some biult up pressure, it did a little ppsstt and that was it. And it still is locked up. I dont think I threw a rod or any thing because it was just idling. I dont know if it has do with the temperature out side and the stuff being more brittle (25 degrees), but I dont think that would be to cold. PLEASE HELP ME.