Prop question

[Robert Jordan]

I have a question I hope someone can help me with. I had reported a few weeks ago I had purchased a new 75 hp Optimax for my 2002 Tracker Pro Team 175. The motor runs great but after running the motor for over three hours my first time out in the verticle position varying my rpm's as instructed I couldn't help but trim it up just a little at 4500 rpm's just to see how it would respond on my way back to the ramp. I just barely touched the trim switch, not trimming the motor more than two inches and the boat started to porpoise. The dealer put a 21 pitch prop on the motor. He said that is the prop that usually works best on that particular setup. He said we could trade out props if necessary. Is that my problem? I had absolutely nothing in the boat such as tackle bags, rods, etc. Some people say a hydrofoil will take care of the problem but I would rather not go that route as I don't feel that is addressing the real issue. I bought this boat new and it is the only boat I have ever owned. I never had this problem with my old 40 hp so I am unsure what to do. One article I read indicated The motor may need to be set up higher. As it is currently set up it can be raised two more holes. So what do some of you think my problem is?

 

[john horn]

Try trimming it down

 

[Bruce Freeman]

I would not change anything until you get the engine broke in and the boat with a full load. Then see how your holeshot is and how many rpm's you are turning at wot trimmed up.



BF

 

[Robert Jordan]

I had run it trimmed down all the way. It was when I tried to trim it up just a little bit that it started porpoising. One article I read said just a small amount of weight in the front of the boat will make a big difference. I haven't been able to get out any more due to the frigid weather we have experienced in our area the past two weeks.

 

[Bruce Freeman]

Once you load all your fear in then you will need to move it around to find out works best. Just think about what that outboard weighs hanging of the back of your boat vs what the empty hull up front weighs? That's why I suggested you not mess with the prop until you have the boat with a full load. I am not an expert but I have learned a lot here and on the water. You said you tried this @ 4500 rpm? It will be a whole new deal with the engine at 100% instead of 75%. Take your time, break it in right and then drive it like you stole it.



BF

 

[Robert Jordan]

Thanks Bruce. I just tried to trim it for about 10 seconds. Trimmed all the way down it runs great and jumps up on plane. This weather is hindering everybody in the eastern half of the country. I want to go fishing so bad I can hardly stand myself!!!!!!! I am very happy with my new motor and I know it will be a huge difference in respect to the 40 I am used to.

 

[Scott Hammer TOXIC]

Also if you are porposing you are trimming up too early before your boat has the speed to keep it on the pad. Break it in, load it up then start playing with setup. We will help.



TOXIC

 

[Robert Jordan]

Thanks Toxic!