When I flush my Mansfield toilet there is one big bubble that comes out of the smaller hole before the water goes down the drain. I can feel the "burp" under the floor. Solids and toilet tissue will clog if I don't hold down the lever. Any ideas on a fix? I dumped a five gallon bucket of water down and all seemed okay. Toilet came with house built in 2007. I have a snake but not a toilet auger. I'm ready to pull the toilet, just too lazy.