Hello, Homedepotcustomer - We're sorry to hear about the issue you're having with your chainsaw! This issue may be related to chain stretching. (Before replacing the bar, chain, or adjusting the chain tension, stop the motor, wait for all moving parts to stop, disconnect from the power supply or remove the battery pack. Also, wear protective gloves.) All new chains will stretch during the first 20 minutes or so of use. So, when you are using a new chain, you will have to re-tighten the chain every 5-10 minutes or the first 20 minutes to get your chain to the right tension. This happens because new chains have not been heated up before, so when they heat up on the saw they stretch. After you get about 20 mins of use on the chain, it will not stretch or shrink, and you will only have to check the tension before starting a project. Would you please send us an email at Reviews@RYOBItools.com? We'd be glad to provide some assistance!