Changed Lawn Mower Motors and Cant Get it to Start Briggs and Stratton Motors

I replaced a 12 hp briggs and stratton motor with a 16 hp vanguard briggs and stratton motor on a 38 in riding lawn mower. There were 3 wires hooked up off the existing motor to lawn mower a red wire that went to motor or guess would be stator, a yellow wire that was hooked to the throttle plate and a red one that went to the starter. The new motor has 4 wires coming off of it and I hooked the red wire up to the starter, the other red wire up to the red wire to the motor, and I done numerous things with the other wires but it was not right. The motor turns over fine but does not start any advise on what I need to do would be appreciated

 

Hard to make a guess...You posted no information for us to go by... model numbers of the engines, mower, or colors of all wires going from the mower harness or the engine. Check for spark and check for fuel.

 

Is it possible that the engine turns over and I have spark but these other wires are something that keeps it from starting suppose to have a connection to a safety device. Just wondering if that was the case would the motor turn over.

 

Yes, it's possible. It'a also possible to fry the coil and the alternator if you connect the wires wrong.