Hoping someone on here can help me...I have a Simplicity Regent 18HP with a Briggs and Stratton engine riding lawnmower. We are having trouble getting it to turn over, all connections are clean, wiring is good, we removed the starter and had it checked came back good, we were told to replace the cellanoid which we did and then we also replaced the starter switch (key), battery is full...We still can't get it to turn over, it acts like it wants (maybe 1 turn) to but then it just drains the battery, it's almost like the starter isn't big enough to turn over the engine. We are at a loss, and I am running out of patience and money..Any ideas?