I have installed a new toilet in the basement. The rough in was already there, I just fisnished it. When I flush the toilet it sometimes clears the bowl properly, other times it takes 2-3 flushes and others it has to be plunged to clear the bowl.

I have read about venting and distances to stacks etc. I am about 20 feet. Could that be the problem? I have snaked the line and it is clear. Could it be the distance to the stack? Would a pressure assist toilet solve the problem?

Thanks,

When I was the service manager for a large plumbing company we used to get calls like yours. "The toilet does not overflow; the water reaches the rim and gradually subsides, leaving the waste and a small amount of water in the bowl."
As a rule in older toilets this would mean a blocked jet butI was getting these calls on toilets that we just installed in our new construction. So when we got a complaint that one of our new toilets was having a flush problem I went out on the call. After a few calls I found the trouble. When our installers set a toilet the wax ring would spread in instead of out. This choked down on the opening setting up a back pressure that stopped the siphon action of the flush.
The remedy was to pull the toilet and form the wax seal so it beveled out and would spread out instead of in blocking the drain opening. I would have this checked first. After our plumbers began to bevel the ring out out complaints stopped. Good luck, Tom