I have a yowza keewadin treadmill I bought used 5 years ago. I started to have belt slipping issues I replaced both the walking belt and the drive belt within the last 2 years. I have been lubing it with a spray silicon lube per the manual, however I was having to lube it every week. I tried lubing with a liquid treadmill lube and did a very thorough lube job as the deck and belt were very dry. Since then the belt has been slipping I tightened the belt it helped but it is still slipping. The slipping is worst when I first start the treadmill and it's better within 2 minutes. Any thoughts?