Re: new to me bayliner
The biggest danger of racing a motor on muffs or tanks is the possibility of overheating due to insufficient cooling water. One of the most common "destroyer" of outboard motors is overheating which can cause piston ring failure and eventually cylinder scoring. Overheating greatly reduces lubrication of the ring and cylinder and can result in catastrophic damage in matters of seconds. In fact, it generally takes as little as 15 seconds from a total loss of impeller at WOT speed to damage rings and cylinders.
If you try to race your engine while in a barrel, make sure there is a continuous flow of water into the barrel to ensure proper water heat exchange and also water level. Or better yet use a large barrel and not just a trash can barrel. With a prop spinning at high speed, it creates air bubbles causing cavitations in the impeller thus reducing water flow into the engine which can cause overheating regardless of the size of the barrel.
On muffs, with a positive pressure from the faucet, there is this wrong impression that same water pressure will provide sufficient cooling thus racing the engine should be OK. FALSE. The muffs can only hold so much pressure before it starts leaking all over its sides. When faucet is opened all the way, you actually get less water into the impeller because the water pressure lifts the muffs off the water inlet surface thus providing a less resistance path for water just to leak off the sides rather than going to the impeller. And if you race your motor, guaranteed it will overheat. Remember the muffs basically are for flushing the motor only and minor engine run testing.
Bottom line, do not race motors while on muffs or small sized barrels. If you must you should only do it intermittently and not to exceed 3000RPM a couple of seconds at a time.
