Yamaha F60 and Lowe 160 question

[thewiz1969]

I just bought a new Lowe 160 boat with a Yamaha 4-stroke 60hp on it and have a couple questions. When I full throttle it from a stop it planes in about 5 seconds but then when I start to trim the motor up for more top speed the front of the boat stays flat and seems to plow? The dealer mounted the motor as low as possible. Its in the very top bolt holes on the motors bracket. Also when at wide open throttle the motor is turning like 6500rpms. I BELIEVE it to have a aluminum 14 pitch prop on it but not sure. I read the manual and it states that 5500rpm is max safe RPM. I need some recommendations on the motors mounting height and the prop pitch. Thank You in advance.

 

[jim dozier]

Re: Yamaha F60 and Lowe 160 question

If the engine is supposed to max at 5500 rpm you need a prop with more pitch (bear in mind your max rpm should probably be measured with the boat loaded like it usually will be used). Pull the prop off of the engine and look for stamped markings that should identify the prop diameter and pitch. The cavitation plate should be approximately even with the plane of the bottom of the boat.

 

[thewiz1969]

Re: Yamaha F60 and Lowe 160 question

I removed my prop and it says 10 1/4 x 14P, I called Lowe and they said it should be 10 3/4 x 17P. The dealership raised my motor to help with the front end plowing but I think they went to much, It was in the top whole now they skipped one and its in the 3rd hole. The cavitation plate looks to be about an 1 to 1 1/2 inches above the bottom of the boat now. I hope this doesn't hurt performance any? Im waiting for my new 17 pitch prop to come in so I can test it. I wanted to try just the prop first but they raised the motor also so I guess I won't really now which one helped the most. Thanks

 

[jim dozier]

Re: Yamaha F60 and Lowe 160 question

There is some wiggle room there. Higher is usually better for performance until you start sucking air in the turns or the water pickup for the water pump starts sucking air. Keep an eye on the pee stream and check for cavitation in the turns. Good luck with the new prop.

 

[thewiz1969]

Re: Yamaha F60 and Lowe 160 question

I havent't recieved my new prop yet but with the motor set in the 3rd sets of holes it still planes pretty fast but doesn't make anymore top speed. I guess it will with the new prop. At 5000rpm I am only making 30.3mph. I can't trim the motor but a tiny bit now or the prop will come out the water. I think I may need to drop it back to the 2nd hole, but Im going to wait and see with the new prop.

 

[thewiz1969]

Re: Yamaha F60 and Lowe 160 question

I installed my new 10 3/4x 17 and now the motor seems flat. It won't turn over 4800rpms. I lowered the motor back to the second hole set. Im thinking a 10 1/4 x 15 stainless or a 10 1/2 x 16 aluminum may be the one I need

 

[Semloh]

Re: Yamaha F60 and Lowe 160 question

Tweak it!