I have a proform 770 ekg treadmill and it stops running after about 30 minutes. The motor smells hot and I also feel like the belt slows and speeds up while I'm walking. I have tried taking off the cover and running a little fan on the moter to keep it cool, but it still stops. I have called sears, which is where it came from and they won't tell me what the problem might be without coming to the house. I know that there is alot of these kind of treadmills that have the same problem , I have been surfing the net for answers and have found alot of people with the same problem.

I suggest you to check ProForm 770 ekg treadmill manual to find out!

Having same problem. Just started this week. Have had mine in storage for a couple of years. Just got it out 1st of the year. Believe motor is overheating.
Was working just fine till now

Sounds like the motor is overheating and depending on the weight thats getting on it, it could be causing the motor to over pull and therefore makes it smell and stop running. of course sears are not going to tell you what the problem is because they want that money but did you buy an extra warranty with it if so tell them to get their butts out there and tell you what is going on with it. i hope that i helped you in some kind of way. please no that i am not being funny or talking about anyones weight, just trying to help.