I recently bought a 97 225 Johnson Ocean Runner and had the VRO disconected. The warning horn will sound a constant tone sometimes. It does it when I first crank the motor sometimes and once did it after it had been running about 30 minutes. It even did it not running in my driveway when I forgot to turn the key off. I replaced the fuel filter and the water coming out of the pisser is not very hot. I know that it is getting oil because I mix it. Could it be a bad sensor?