Logo

Outboard Height Position

CrashTackle

New member
Hi,

I have a Suzuki 40 two stroke I bought some years ago. The boat is 4.15 mts of about 14 feet. It was still under warranty, so it was basically new when I bought it.
I bought the boat from a guy who modified the height of the motor and lifted the motor about 2 inches.

My issue is my sounder has always been playing up and is unreliable and losers the height of the water all the time and as I speed up. I had two sounders fitted to the boat so it was okay and get a reading off one of them. Both of them will wash out.

I generally use the boat in creeks and shallow water so I am keen to have my sounder working well. I retired lately and the boat is getting used now. I decided to buy a new sounder and replace the one for the driver and fit that one down the front of the boat as the front one was an antique.

I still get wash out with a new sounder. I notice a lot of turbulence at the back of the boat. It had a live bait pump fitted and a step up. I removed the pump and bracket and the turbulence was still there so I have shifted the transducer to the other side of the transom. I took it for a run today and it is still the same. I trimmed the outboard and tucked it in under the boat more, and it improves, It is not the right position for the boat, but seems to be in the best place for a reading. Is there a chart to measure the position of the cavitation plate in relation to the back of the boat. It is sitting about one inch about the bottom of the boat when the outboard if trimmed in a normal position.

I am thinking the motor needs to be raised. IS there a guide that will give some advice on the best position

Thanks

Crashtackle.
 
The basic rule is that the engine's anti-cavitation plate (correctly, the anti-turbulence plate) should be even with the lowest point of the transom. That holds if the engine is mounted directly on the transom. If you have an engine offset mounted, then the plate should be raised 1 inch above the lowest point on the transom for each 12 inches of offset.
 
Back
Top