Getting Daydream on a Plane on the Loop

Also the smaller diameter will allow greater RPM--There less flex with the SS prop--all in your favor. Yes the "R" is right rotation.

Agree with Foggy. You want the trim tabs working.

There may be some times as you get on the Great Lakes you may need the speed.
 
Pat, I have had some trouble with the trim tabs in the past, but it was due to a broken line. However, the way I found and isolated the problem was simple.

First, I must remind you, you and I both have 2005 25's. So, I would think they are similar. My first clue that something was wrong was when I couldn't get the boat on plane. My next clue was that I have a indicator just below the up/down switches which shows me the tab position, all through the range. So when the labs failed up, the lights didn't light indicating "UP". In addition, whilst Judy looked at the tabs, over the rear, I tried to make them go down. And I failed; they didn't move. And last, after I added fluid, I could see where it was coming out of the broken line. Cut through by the spare propeller.

So take a look at what the tabs are doing before you fix them. They may be alright and the boat is overloaded and the prop was broken. Check first.

Boris
 
Today's report, the "new' old prop made a significant difference...WOT gave us 5000 RPM, right at the bottom of the spec for a BF150 (5000-6000). It popped right up on plane even though the trim tabs are not working. We crossed Lake Ontario today running at an easy 3200 RPMs at about 9.5 statute mph, as low as it will go and still stay on the plane. We burned some extra fuel, but it turned what would have been an 8-9 hour crossing into 5 hours. I think though our weight still is a problem. Running at 5000 RPMs we were using a LOT of fuel., not something I would want to do except in an emergency!

Boris, I checked the reservoir for the ATF for the trim tabs - it has the recommended 2" of fluid in it. I looked for a loose wire or a fuse at the switches, did not see an inline fuse or loose wire. However, the tab position indicator light has one light (the right one) that is blinking steadily. I will probably just get this repaired when i get home, since we can get on the plane without the trim tabs, and for the most part, slow cruising is working for us.
 
Pat, I question that the boat is really efficient at 9.5 S MPH. I think you would have gotten better "mileage' at 14 mph or so. This is where the flow meter, with GPS can give MPG--not sure if you have that ability.

Glad you got across the big lake.
 
thataway":1rzf6b2w said:
Pat, I question that the boat is really efficient at 9.5 S MPH. I think you would have gotten better "mileage' at 14 mph or so. This is where the flow meter, with GPS can give MPG--not sure if you have that ability.

Glad you got across the big lake.
Click to expand...



Bob,

We were carefully watching the RPMs, the Navman flow meter and the speed. 9.5 mph was as efficient as we were going to get. WOT, 5000 RPMs, was giving us 14 or 15 mph, but the fuel burn was horrendous. At 9.5 mph we were burning 3.8 gph. At 14-15 mph it was 9 gph and climbing when we pulled it back. I could be wrong, but I think everybody is really not appreciating how heavy we are and how that affects everything.

Pat
 
OK, just one more post. It was 102 F outside today so I have a lot of free time.

Pat, I appreciate how heavily loaded you are. I know that the 25 really can be loaded and then goes slow. Judy has learned how to pack Journey On full for our trips and the gas mileage is abysmal.

And if the weight isn't forward, it needs trim tabs.

Boris
 
Pat,
Thanks for the numbers. You appeared to be getting 2.5 mpg at the 9.5 mph speed, and 1.6 mpg at the 15 mph. (That 1.6 was like I was getting with a 28 footer and 300 hp)... At the 15 mph you appear to be using about 126 HP, at the 9.5 mph you appear to be using about 53 hp. I was questioning if you were really planing at 9.5 mph, especially with heavy load. Always hard to tell at low speeds. Usually when you "get over the bow wave", the fuel consumption decreases. Only if you did that at the 9.5 point, instead of still being on a ascending curve of fuel consumption. No matter, if that is best speed for your "fast" go for it".

in a "light' C dory the planing speed is about 15 mph, and the worse displacement speed is about 10 mph. I realize that there are lots of variables, and comparing the figures on a very light boat are difficult. It would be interesting to compare speeds from 1000 to WOT speeds. Bottom line is that you are now getting to speeds where you are not lugging the motor!
 
Our experience was different: the most inefficient speeds for our 25 were between 9 and 12 knots. As heavy as you are, I am surprised it could stay on plane at 9 mph. The boat is having to work hard to get over its own bow wave at that speed.

Our experience with the Navman: the read out is not instantaneous. It would read high when the throttle was pushed forward, then (given some time) would settle down. Trim to get the most efficient fuel burn at a given speed/RPM.

And, sometimes to get somewhere, you just use whatever fuel is necessary to get the job done (as long as you have plenty of reserve).
 
Pat,

I'm sure you're ahead of me on this, but I used to look at GPH when judging fuel burn rates.....nothing wrong with that. But I noticed that I was lazy about converting the readings into what really counts when going from point A to point B; namely, MPG. At the higher RPMs, one surely uses more fuel per hour (except just after the planing transition), but one also goes more miles per hour.

Here are numbers I got in 2015 on the Honda 150 before it blew up. Of course, I was not heavily loaded like you are. Last year we took a 8 day cruise to Canada and were loaded heavy (not as heavy as you, no doubt), and I was amazed how sluggish that made everything.

RPM; MPH; GPH; MPG
3000; 9.7; 4.5; 2.2
3500 13.0; 4.6; 2.8 (just planing)
4000 17.9; 6.5; 2.8
4500 23.0; 7.7; 3.0
 
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