28 Prop Size/Pitch

[Bullish]

I dropped my props off today to have them reconditioned. He was surprised that they were stamped 17/24. He is used to seeing 17/21 on our boats. Also, at first glance, he thought that they were bronze and not nibral but too dirty for him to tell. Would any of this concern you?

I bought the boat new so I expect they are the props the factory put on the boat.

[Split Decision]

If they are factory original, I doubt they are bronze.

Where did you end up taking them. I just sent mine to Atlantis in south Jersey.

[Bullish]

Atlantis also...

I had to be in Philly today so I stopped in Mt. Laurel at their shop to drop off the props and meet Ray. He is going to use the prop scan system on them. I am only turning 3550 rpms on each motor and should be turning about 3800. I hope the props are the problem. He wants to take some cup out but I don't know why we would need to change cup because I used to get 3800 rpms with these props. If anything, I would think over time the cup would flatten out and you might get higher rpms.

This is my first inboard boat so still learning much that is specific to inboards.

I am concerned about him taking cup out when the problem might be fuel flow related.

[Split Decision]

Don't ever take the cup out. If something need to be changed, take it out of the pitch. Mac will also tell you not to take out the cup.

Are you going to pick up your props when done or send them to a pickup point in Pt. Pleasent.

[Bullish]

Perhaps he said that he was going to take pitch out....not cup. We are going to talk again before he does anything.

I haven't decided on shipping yet. I don't go south much this time of year. Would it be cheaper to ship ours together to my house or your house? Might give us a reason to get a beer.

[Split Decision]

They have a drop point in Pt Pleasant. We could take a ride down together if you want.

[usrower]

Props

Be very careful when you get those props checked. I took mine to a guy in the Cape May area (Eastern Propeller) who used the prop scan system. I ran into a similar problem as you only I was spinning higher rpms than recommended by the manufacturer. It turned out that after the reconditioning was performed, the rpms dropped but I never obtained the top end speed I expected. So I had the props checked by the guy who does work for the factory and it turned out that the props were way out of spec. I would talk with Mac before I would let anyone do anything to your props.

[Patriot]

Bullish- something else to consider is to leave your props alone and buy a set of Acme Nibrals directly from Mac. He gave me a great price compared to what Acme sells to the public for. Sometimes by the time you have all these prop doctors work on your blades the cost is approaching the cost of one new prop. If you don't have Acme's now it is worth considering as your performance will be much better with the Acme's and you will then have a spare set of props. MAc or Keith will tell you exactly the Acme you need for your power.

[Bullish]

Patriot,

Thanks, most everyone seems to be happy with the Acme. I've talked to Keith about Acme and been considering for a while. I decided to wait another year.

[Bullish]

I talked to the Prop shop this morning. We are going to take 1 inch of pitch out so effectively, I will have 17x23 instead of 17x24. He thought this should give me about 200 rpms more which is what I am lacking.

He gave me a good idea....I wish he had told me last month when my boat was in the water. Since I am 300 rpms below where I should be at WOT, he suggested that I put the boat in nuetral and see if the engines will still put out correct rpms at WOT. If so, we would know for sure, that the problem is not engine related....the problem would probably be prop and /or boat bottom related.

Tom, I think I'm going to pick up the props in Pt. Pleasent one Saturday morning in December and keep heading south down to the boat. I'd like to do a few more boat chores before it get's too cold.

[Patriot]

He gave me a good idea....I wish he had told me last month when my boat was in the water. Since I am 300 rpms below where I should be at WOT, he suggested that I put the boat in nuetral and see if the engines will still put out correct rpms at WOT. If so, we would know for sure, that the problem is not engine related....the problem would probably be prop and /or boat bottom related.

Bullish- on a mechanical engine the no load test really isn't going to show you much. Yes, it will tell you if your throttle is really being avanced but the reality is that when there is a load on the boat the engines work a lot harder. You could probably have any number of things under performing on the engine and still make no load rpms.

[Bullish]

Good to know. Well, hopefully, the props were my problem. If this doesn't increase my rpms at WOT I guess I'll take a close look at my pick up tubes and filters.

[Bullish]

By the way, you mention "it will tell you if the throttle is being advanced". Not sure what you mean. When my engines fell short of 3800 rpms, I had a little room left to push the throttles. That last inch of throttle produced no more power. Does that sound like a different problem to you? I have the EDC (electronic) controls on the boat.

[JuliaGCC25]

I am not so sure that I would run my engines up to WOT without a load on them. You may encounter an even bigger problem!

[Nicky M]

If you have an EDC then the most rpm with no load is 1500, theres a rev limitater