To turn my boat motor over to check for spark or compression do i need to have it in water?

Question

My boat seems to not be running with as much power as it should when a get on the throttle. I have never owned a boat before so am new to this. Do I have to have my motor in a tub of water to turn the motor over checking for spark and compression? Does it have to be in water to run even if you don't engage the transmission into foward or reverse, but rather to just have the motor idle?

Answer 1

Having it idle out of water is fine, but some of the transmissions require back pressure from the water to function correctly.

A boat motor is basically the same as any small motor (or large, it depends on the size of the boat).

The only difference is what they are connected to.

Answer 2

Well Inboard mounted engines will have a water hook-up to run an engine for testing and short runs. Outboard engines which usually hang from the rear won't have this option. To check spark and compression the answer is NO in both types. Inboard would be classified as your engine and final drive are in the boat with your output shaft going through a stuffing box to the outside rear of your boat. The water not only cools the engine,but also cools the exhaust manifolds to reduce the heat inside the boat. Your out board is typically just a complete unit that you can put on and take off. If you need to run an out board you need a 55 gallon drum with the top cut off. Mount a 2x6 board to the drum to hang the engine on, this represents the rear of the boat and gives the drum rigidity. FILL THE DRUM UP BEFORE putting the engine in, that way you don't have to worry about it all tipping over. OUCH! You then can run it at idle, LOCK THE TILT and in gear at speed. It's gonna SPLASH, I hope this helps.

Answer 3

even idling the engine needs cooling, and it has to have water for that.

But if you just turn it by hand to check compression, it's not running, no heat, no water needed.

Answer 4

In all reality you should never turn a bout motor over without the lower unit being in water. It can damage the impeller ( water pump ) Now with that said, do I do it like that...... No. I will only put it in a tub of water or put the ear muffs on when I am actually starting it............ My suggestion, check your fuel system. the lines from the gas tank ( including the fittings ) to the carb..... trust me, I melted a motor because I did not do this

Answer 5

You can use what a lot of people call "Micky mouse ears"The are like headphones for your lower unit and supply water through a garden hose,you can run a marine engine as long as you like with this device.

Answer 6

Yes you can put the muffs on to run it as long as you want. You dont want to go to WOT on the hose though. You can run up the RPM's but jsut keep an eye on them. But for what you are wanting to do you dont need it running. Pull all plugs, do your compression checks, get a spark gap tester and crank over to check spark.