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30 is about right for a 25hp on a small skiff at least that is what I'm hoping for with my new skiff. Im getting 21mph with my current 1436 flatbottom Jon set up with a 15hp merc 4stroke.
Yeah, I looked at some photos of your boat. I'm impressed. There are times when I'm in a rush when I'd love to be able to hit 50 and 60+ mph, but those times are rare. Besides, when I've gone that fast in a flat's boat before, you kinda feel like you could simply get blown overboard any second. When you're cruising the 20 mph range, you're not burning a lot of fuel, you're not slamming off a chop, and you'll get where you need to go soon enough. You will DEFINITELY gain speed with the 25 on your boat.
 
One thing I don't like about the new Yamaha F25, and it's probably the only thing, is that when I'm running over shallow mudflats (not grass flats) but mudflats, and hit bottom, the engine isn't capable of powering through that shallow spot like a more powerful horsepower would be. Explained a little better, there are times when I'm only trying to get across 50 feet or so of a particularly shallow area. There's plenty of water for my hull; just not enough to run through it with the engine. I have it tilted up as high as it will run without porposing. My skiff has a flat bottom, but a friend says I would still benefit from adding a jack plate. I thought a jack plate would just cause my prop to cavitate with a flat bottom boat and no tunnel. However, I heard I was wrong about that and that I would gain a bit more shallow water access. I'm looking at the micro jack plate, that weighs 23 or 26 pounds from TH Marine.
 
Yeah, I looked at some photos of your boat. I'm impressed. There are times when I'm in a rush when I'd love to be able to hit 50 and 60+ mph, but those times are rare. Besides, when I've gone that fast in a flat's boat before, you kinda feel like you could simply get blown overboard any second. When you're cruising the 20 mph range, you're not burning a lot of fuel, you're not slamming off a chop, and you'll get where you need to go soon enough. You will DEFINITELY gain speed with the 25 on your boat.
The f25 will not be going on the boat in the pics. I am getting a 14.6 skimmer skiff custom built and the F25 will go on that. The Jon boat will be for duck hunting.
 
I have a very light tiller waterman 16, old model with no walking gunnels and no deck. When I bought it, it had a 25 merc 2 stroke which was known to be more than 25 hp and with 2 men and almost no gear it topped out at 28mph. 34 is still hauling. They should sell a buttload of those motors with that kind of performance.
I'm sure they're hoping they will. This F25 is on a 16ft skiff that was built with light marine grade plywood, then fiberglassed together. I don't know what it weighs, but it can't be much.
 

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One thing I don't like about the new Yamaha F25, and it's probably the only thing, is that when I'm running over shallow mudflats (not grass flats) but mudflats, and hit bottom, the engine isn't capable of powering through that shallow spot like a more powerful horsepower would be. Explained a little better, there are times when I'm only trying to get across 50 feet or so of a particularly shallow area. There's plenty of water for my hull; just not enough to run through it with the engine. I have it tilted up as high as it will run without porposing. My skiff has a flat bottom, but a friend says I would still benefit from adding a jack plate. I thought a jack plate would just cause my prop to cavitate with a flat bottom boat and no tunnel. However, I heard I was wrong about that and that I would gain a bit more shallow water access. I'm looking at the micro jack plate, that weighs 23 or 26 pounds from TH Marine.
I am getting the Atlas microjacker on the new skiff as well. I am hoping it is worth the money and the extra weight. I don't have power T&T so it will kind of take the place of that.
 
you can take advantage of a jack plate without a tunnel but you will need a well cupped prop or it will just blow out at speed.
When you say "blow out at speed" are you referring to running the motor way up for running in skinny water? All I am wanting the jack plate for is dialing the motor in while running for performance, idling off flats, and picking the motor up while poling. I do not have trim and tilt so I figured this would be alternative that would help me get better performance. Am I right on this? Never owned a hydraulic jack plate.
 
So finally got to run my 2017 Yamaha F25 today. Here are the numbers I got. I haven't got a chance to set up the boat or distribute the weight properly so this wasn't with the boat loaded down or anything.
I got up 31mph at 5500 rpm going into the wind on my lake so there is no current. I never ran it at the top of the rpm range so I'm guessing I can get a couple more mph out of her. The engine is smooth running but rough at idle. Hole shot is decent figured it will get better when I'm able to put some weight forward. I will post more once I have a chance to dial it in. This is how it is set up as of now. GPS numbers were off of phone gps because I'm currently having problems with my dragonfly pro 7. But the numbers on the phone have been reliable in the past.
 

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I run the PT SRA3 10p prop on my 1448 Alweld flat bottom with the new f25 and i run around 28mph 5800rpm. I have a manual jackplate with 6in of setback. I run the motor about 2in above the bottom of the boat. The SRA3 performs really well compared to the stock aluminum prop when it comes to takeoff and preventing blowout.
 
I run the PT SRA3 10p prop on my 1448 Alweld flat bottom with the new f25 and i run around 28mph 5800rpm. I have a manual jackplate with 6in of setback. I run the motor about 2in above the bottom of the boat. The SRA3 performs really well compared to the stock aluminum prop when it comes to takeoff and preventing blowout.
I run the PT SRA3 10p prop on my 1448 Alweld flat bottom with the new f25 and i run around 28mph 5800rpm. I have a manual jackplate with 6in of setback. I run the motor about 2in above the bottom of the boat. The SRA3 performs really well compared to the stock aluminum prop when it comes to takeoff and preventing blowout.
What company makes the jack plate you're using and what model is it?
 
What company makes the jack plate you're using and what model is it?
I run the T-H Marine manual jackplate. I installed it myself. Super easy to install if you have an extra hand available. I do wish I would have went with a hydraulic jack plate, but mine was only $180 vs. $800. My boat performs well enough with the manual for now.
 
I run the T-H Marine manual jackplate. I installed it myself. Super easy to install if you have an extra hand available. I do wish I would have went with a hydraulic jack plate, but mine was only $180 vs. $800. My boat performs well enough with the manual for now.
Ok, so you went with the manual jack plate. Those are hard to ignore because the cost savings is tremendous. Why do you wish you would've gone with a hydraulic? Is it what I believe would be the obvious reason of not being able to adjust the height of your engine while underway?
 
I am actually in the process of buying a used atlas microjacker from a fellow member here because I found that when adding additional people in the boat and wind conditions really changes the performance of the boat. Head wind would make the boat porpoise terrible bad. I don’t have electric tilt/trim so I figured that a hydraulic jack plate would give me a chance to correct these issues while running. I think the manual jack plate would work great if you have electric tilt/trim.
 
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