Is my motor too heavy?

[stl]

I recently aquired a 1965 9.5 hp Johnson model number mq11c. I changed the water pump and rebuilt the carb. It ran like a dream in a trash can. I finally got to take it to the lake this weekend. I put it on my 14 foot semi v and would not even attempt to start. When I got it home this evening I put back into the can and it ran great. This motor is quite a bit heavier than the 5.5 that I usually run on this boat. I did notice that it sits alot lower in the water than the other motor. The 5.5 Johnson seems like it sits on top of the stern bracket, while the 9.5 sits behind it. I don't know if that makes any sense, but I am worried that the motor is sitting too low in the water. Maybe you guys might be able to help on this.

 

[kajnjim]

Re: Is my motor too heavy?

Where is the cavitation plate in relation to the bottom of the boat?

 

[stl]

Re: Is my motor too heavy?

You know I really did not check but I but I would guess that it was about 6 inches below the bottom of the boat. I am looking at it on the motor stand right now and this is my guesstimation.

 

[kajnjim]

Re: Is my motor too heavy?

General consensus is within 1" of bottom of hull.

 

[stl]

Re: Is my motor too heavy?

Would this make it not start?

 

[swimmin' for shore]

Re: Is my motor too heavy?

No way. If you're in enough water, I'd think it should start. My last motor for an aluminum boat I'd fixed was 12" below the bottom of the hull. It tended to bog it down a bit, but the motor started up fine...whenever it wanted to.

 

[Tacoma01]

Re: Is my motor too heavy?

I'm NO expert here but did have an older outboard that didn't like to travel in the car. Turned out to be a sticky carb float. Try taking the motor cover off and tapping the carb bowl ( not wacking) once you have the motor installed. If the float is sticking this often free's it and allows the carb to do it's thing. BTW, I also had to start mine with the choke off when this happened. HTH ( but again, no expert here.)

 

[stl]

Re: Is my motor too heavy?

I was really worried that it sat too far in the water, and got water in the cylinder or something like that. I dont know if it is a carb issue because it runs fine on the motor stand. When I did have it on the boat and it wouldn't start I did squirt some fuel in the carb and nothing. This has really got me puzzled.

 

[stl]

Re: Is my motor too heavy?

Any other thoughts on this? Please help.

 

[itstippy]

Re: Is my motor too heavy?

The motor is not sitting too far in the water to run. Do not worry about that. You will not get water in the cylinders by mounting it onto a boat transom that sits low. <br />Tacoma01 may have hit the problem on the head with the idea that the float is sticking due to traveling. Give his idea a try. By the way, you CAN get water into a cylinder if you remove the motor from the water (trash can or lake) and tip it so that the engine (powerhead) is lower than the propeller. There is still water in the "leg" and it can drain into the cylinders through the exhaust ports if you get the top of the motor lower than the bottom when you're putting the motor in the trunk of your car. Do not do this.<br />If you are really curious about water height, get the trash can and mount the motor on the boat in your driveway. Fill the trash can so the water is at the level where you know the motor runs well on the horse. Start the motor. Add water to the trash can until it's level with the bottom of the boat. Does it kill the motor? Don't worry; it won't.

 

[stl]

Re: Is my motor too heavy?

itstippy, I think you may have nailed it. Check this scenorio out for a second. I test run the motor in a can a few days be for I take it up to the lake. Water may still be in the leg right? Now I transport it on its side in the back of the truck, carry it down to the dock. Lay it on its side, get in the boat. Now I distinctly remenber hoisting it way up in the air to put on the transom. This thing is really heavy from a seated position, but I am almost sure I lifted the prop above the powerhead when I did this. After I knew it wouldn't start I stored it upright until travel the next day. I am almost sure you are right, at least I hope so I have been losing sleep over this.