This is the second replacement tank and they spring hairline cracks. Also the trimmer does not run right. I have cleaned the carb, exhaust ports, yet I still need to run with the choke at half way for a few minutes before it will run with the choke open. I can then put the trimmer down for a few minutes and it bogs again until I run it with the choke partly open for a few minutes again. I have to slowly open the choke a little bit at a time while using the trimmer. So, I am not sure what is wrong and I wonder if the gas tank is somehow pressurized and causing leaks. I had put a new cap on the tank a while ago, but that had no effect. Thanks.