Motor too high?

[jtmaxdad]

I have a 95 170tf. I've had it a few years now. I noticed that a previous owner had apparently raised the motor up one hole from the original mounting.
I know not what you lose or gain by doing this. I have tried several different pitch props, down to a 19 and still can't get the trimmed out top end rpm I would like. About 4800rpm tops.
Wish I could afford a jack plate.
If anyone knows if I should put it back where it was originally, please share.

 

[DodgeBoy]

I thought the same thing on my 2022 V19. I could see marks from the washers on the holes above and below the location of the motor. I noticed the motor would caveat if I trimmed the motor past the first line on the gauge. So, I figured I would have the motor dropped one hole. That didn't work out to well for me or the boat. I lost speed, fuel mileage and the boat now points to the sky when taking off from a stop. I was told by the dealer that the factory testes every boat for the correct prop and motor location. This means the motor holes will have multiple witness marks on the mounting plate. They told me that I would need to have it put back or change to prop! The lower the motor the stepper the pitch on the prop do to more drag from the motor being in the water deeper.

If you know for a fact that the motor was moved, try putting it back and install the original prop back on the boat.

 

[92 Nitro 190dc Owner]

A standard starting spot for which bolt hole to use begins by measuring the difference between the anti-cavitation plate on your outboard and the bottom of the hull. The anti-cavitation plate should be approx. 1 inch above the bottom of the hull as a starting point. Depending on how your boat performs on the water, (porpoising, sluggish, poor maneuvering, etc.) you may want to raise or lower the outboard. Ideally, your anti-cavitation plate will run just on the surface of the water. After you've determined where to place the outboard's height, then you can focus on the correct prop. Determine your outboard's upper rpm range based on the manufacturer's specification, then while on the water at WOT, see if the prop is within that range. Based on your rpm reading, you can then determine prop pitch.

 

[CincyGus]

I was told the same thing DodgeBoy was told but I'm not sure I buy it. I looked at Targa V-19's for 2 years while I owned my 175TXW, every time I went into Bass Pro Shops. Motors were mounted in different holes on same models with same engines. Sometimes the second from the top, sometimes the middle hole. Same deal on the 175txw's although it was the top or second from top for those motors. I mentioned that to the service rep when I picked up my 2023 Targa as it's mounted in the middle hole and I thought that might be too high and need to be dropped one to the 2nd hole. He had no answers on why if they were tested, they come in with them mounted in different holes. Just said to test it out and if it needs to be adjusted, they will move it for me.

 

[92 Nitro 190dc Owner]

Bottom line... you have to experiment until you find the setting that works for you. Some like more speed, some like more pulling power. Setting the outboard approx. 1 inch above the bottom of the hull is just a starting point. I doubt very seriously that every boat is factory tested before being sent to the distributors.