Outdoor Power Equipment and Small Engines - Mower starting issues

I have a briggs and stratton intek v-twin on my riding lawn mower. For the last couple of years it has had issues turning over to start. Each time i've had to recharge the battery to get it to start. Each time it struggles to turn over but eventually it will turn over and start, and run the rest of the day. I bought a new battery it ran fine the first time. Next time, had to charge the battery. This time, the battery was charged and it still can't turn the mower over enough so that it will start. Decided to put jumper cables on it, and still had the same problem. Engine barely turns over, and not fast enough to create a spark to start the engine. Any ideas would be appreciated. Thanks in advance.

You need to adjust the valves. They have become too loose.

Thanks, I will try that tomorrow and see what happens.