Okay so I bought a second hand baby lock bl4-838D yesterday. Use it for a few minutes last night and then today sat down to get some work done. Was serging great then (after 30 minutes) started to get slower and slower. I turned it off, turned it back on and it was back up to speed for a minute and then slower and slower. There was just the tiniest bit of burnt engine smell so I checked to make sure everything was clean then let it rest about 15 minutes while I used my sewing machine to do a few things. Now the serger turns on and does nothing when I hit the foot pedal. I can manually turn the wheel and everything seems to be moving properly. Do you think the engine is gone? Thankfully it has a 30 day warranty but I will be gutted if it's broken already and don't know if I will trust a used one again.