Hiteck22

I did lower the engine and it didn't really change anything. When the boat is fully in the water and I am ramping up the RPM's to get up on plane I do see up to 10psi. But as soon as the boat comes up onto plane that goes back down to 7.5-8 and stays very consistent at that pressure. I have solicited as much feedback as I can locally and the general consensus was if it is cooling right then the lower than expected water pressure isn't a bad thing. the 12-15 I am seeking is technically the maximum pressure. I want to take that advice and and go but I fear I will always be suspect of this until a cause presents itself or I figure something out and I would love some peace of mind.

Understood. The water pressure at idle isnt the concern for me, it is the 7-8psi at 3500-4000 RPM when on plane. That is too low and I am trying to sort out why.

Yes I meant trimmed down. Everything that I read about the break in process said to do the break in at full load. Full gas tank, gear loaded, trimmed all the way down, etc. I bought the motor from a re-man shop. And he said the same this as you, running on the muffs isn't an issue unless you are running above idle. Just to check it off the list of potential suspects I pulled the leg to check the impeller. It was fine but I put a new impeller and gaskets. The passage from the water inlet to the bottom of the water pump was clear/clean. It's a 20" leg btw. I will double-check the prop center to the planing surface tonight. So after doing the water pump I took the boat out and had the exact same performance. At idle I was getting 3-4psi, and on the slow crawl up from idle to getting on plane the water pressure did increase. When I was right at the verve of popping up onto plan (the moment when really plowing water) the psi got up to 10. As soon as it climbed up on plane the water pressure went down to 7-7.5psi. I ran through this cycle 7-8 times and got the same behavior the entire time. I kept swapping over the the engine temp throughout the process and the temp seemed fine. between 90 and 120 degrees depending on RPM/speed. When I was on plane I was seeing the 7 psi in the 3000-4000RPM range. The manual for my engine says pressure at WOT is 12-14. I wouldn't expect to see 10 psi at idle. I know some mercury models get PSI up into the 30's so maybe those get idle pressure of 10psi? I am getting the water pressure from a system monitor gauge. I don't have a tube run to an analog water pressure gauge. I am planning to check the tubing to the water pressure sensor for obstructions. the line comes out of a port on the block. It comes from the block into a tee, one line going up the to water pressure sensor, and the other is currently capped off and is there to connect an analog water pressure gauge. I'm considering buying one to hook up just to confirm the water pressure I am getting off the sensor is valid.

The guy I bought the motor from said to check my impeller. I ran it on a set of muffs for a couple minutes and he is wondering if I toasted the impeller. I'll be checking tonight.

Do you think the low water pressure is a result of being fully trimmed in also? I had the smartcraft gauge set for RPM at the time because I was trying see see how accurate the analog tach was. Then the low water pressure alarm came up and I switched over to that and it was around 7 psi at which point I shut it down.

Just mounted an Optimax 115 to my '97 17.5' procraft fish and ski. The motor is reman'ed so I brought it out yesterday to start the break in procedure, which calls for fully trimmed in and 3000-3500RPM. At that RPM totally trimmed in I was getting rooster tails as tall as the engine and the water pressure was too low.y smartcraft system monitor was squeaking about it and it was in the 7PSI range so I shut the boat down and called it a day after about 10 minutes. I know rooster tails can be a product of running fully trimmed, but I'm supposed to stay trimmed in during break-in, and combined with the low water pressure I figured I was just mounted too high on the Transom. I have the cav plate about 1" below the bottom of the boat. I also only have one hole left to go down, it was in rhe second to lowest hole, so I'm a little nervous that won't be enough to resolve this. Any thoughts? Am I way off in my assessment?

I have recently gone through Prop selection academy at the school of hard knocks and expensive props haha. And what I have learned is 1 inch of prop pitch change equate to roughly 150-200 RPM change. The 24P prop you had is really designed for high speed as compared to lower pitch props. Forgive me if you know this already but for the sake of being thorough, the higher the pitch, the further forward you boat travels forward at speed with each rotation of the prop. So reducing the pitch to a 19 for example you would travel less distance with each rotation, but the physics of that pitch mean your outboard can transfer power easier, meaning better acceleration and torque for getting on plane. The downside is that when you are at speed and on plane at wide open throttle (WOT) it will be turning faster than the 24P. Its like a 10 speed bike, you can't start on the lowest gear (equivalent to the 24p prop) because it is difficult to get started from a stop, but when you are going fast that's the gear you want to be in to travel the greatest distance with each rotation of the pedals so you don't have to pedal so fast to maintain speed. The opposite is true on the bike, if you start in the higher gear (equivalent to the 19P prop & easiest to pedal gear) you can get going from a stop easily, but when you are going fast you would be peddling like a tasmanian devil on meth. Assuming the prop diameter is the same, going from a 19P to a 21P should reduce your RPM's by roughly 300-400 RPM at WOT. You will loose some low end grunt and the time it takes to get on plane will worsen a bit but you wont be running your motor too hot at WOT. Chicks dig $$$ more than speed and you will have less $$$ if you have to re-power the old girl. There are variables, engine mounting height, whether or not one of the props is cupped and another might not be, etc. but the 150-200 RPM per inch of pitch is the rough guideline. Another factor is the material. Stainless props spin faster than aluminum typically so just a swap in materials will have an effect on the RPMs at WOT as well. Unfortunately you need to decide what is more important, the ability to get on plane and do so quickly, or maximum top end speed. A higher pitch prop will give you better top end speed at the expense of torque which will hinder your ability to plane or plane quickly. The inverse is true for a lower pitch prop. So if the diameter is the same, and you should check that, going from the 19P to the 21P should get your RPMs closer to 5600-5700 if you were at 6000 previously. I like to play it safe and am a conservative guy who worries about blowing up the engine, the reason I just played prop whack-a-mole was having to re-power after blowing an engine. Don't worry, it didn't blow because of the prop and thus making this advice suspect haha. If it was me I would skip the 21P and go for the 22P. That theoretically would get you closer to 5400RPM than 5600 RPM at WOT and I would feel more comfortable with that. You should look in your user manual, they are pretty easy to find for free online, and confirm the recommended RPM at WOT. For my boating needs, mostly fishing but no serious tourneys where drag racing to "the spot" is "critical", I value ability to get on plane more than top MPH so I tried to prop for that scenario. Being able to reliably plane out makes boating easier and safer in my opinion. So I think that a 22P would be the safest way to go. A 21P will accelerate a bit faster and help with planing a bit as compared to the 22P but will probably have your RPMs still a touch over the 5500 you are shooting for. That being said, you haven't blown it up at 6000 RPM yet so whats the diff between 5600 RPM and 5400 RPM???? Hope this helps!

I have a '97 Procraft 17FS fish and ski and I'm finally replacing the old existing F.F. with a new one. The bottom step on the transom is curved and the existing transducer was screwed to the transom there, I'm assuming to be near the on-plane waterline, but it ***** the thing at like a 30 degree angle from straight and also positions it right at the edge of the lowest step. It never worked well at any speed, assuming this poor mounting location was the cause. So I was thinking of mounting the transducer off to the right more and screwing into the step surface that is directly above where the transducer will exist. It is away from the edges of the steps on the hull surface, right of the motor by roughly a foot, and could point straight back unlike the old transducer. I would mount a transducer board in the location that I am considering so that I can adjust as necessary, but also to space it down an inch to get the transducer half way below the bottom of the boat so that it can skim. I am curious if anyone sees any major flaws to this plan that I am overlooking that would have a major negative impact on transducer performance, or boat safety I suppose . Another question I have is I have no idea how much of the boat touches water when planing. I am thinking it can't just be the lower step surface and where I am considering mounting the transducer will be at or close to the water line on plane. Any input anyone has before I do this would be greatly appreciated. old transducer location in a bad spot, it is angled and right at the right edge of the lower step. Sorry I cant figure out how to shrink the images down small enough to include 7 or 8 of them. I posted the images to dropbox and below are the links to the images with a description of each image in the link name. Not using the same location with new transducer Would like to install here screwed up into the top surface above the transducer It would be right of the lowest step edge by 6-8 inches and right of the motor by about a foot Will install HDPE transducer board where middle finger is to get transducer spaced down properly to bottom of boat Full transom view. Thoughts?

I don't think there are any carp in the Nashua, at least not in that stretch. I haven't heard about or seen anyone catching them. If you want to fish for carp in the area the Merrimack river in Southern NH or in Lowell is a better bet. Although... Horseshoe Pond in Merrimack actually has a lot of carp in it. I guess it used to be an oxbow of the Merrimack. I accidentally caught one while bass fishing a couple years ago and I have seen them cruising by/near the boat a bunch of times while fishing there. I forgot this from my last post, were they blowing up along what seems like the center line of the river? If so I think you were seeing Perch like LadiMopar was saying. I hear them going crazy all the time behind me when I'm frogging around dusk.

There are no restrictions for bass boats and I have seen plenty of of them in there. The ramp isn't paved, it is just sand and a relatively shallow grade so you will have to back you vehicle up until the doors are practically in the water to get your boat to float off. But it is definitely doable. I launched my 12' aluminum boat there 1,000,000 times although I haven't tried it yet with my new bigger boat :-). If you are standing at the "ramp" looking out at the water there is a bit more water to your left than right so aim your trailer in that direction. You will basically have to back your boat into the pads a little bit. There isnt much parking there but if there isnt any room on the ramp there is room to park on the side of the road that the ramp is off of. It is a mostly private road with only traffic from a few houses that are on the peninsula. There is more vegetation on the inside of the horseshoe than the outside. I have always had the most success on the edges of that than the edges along the outer shore. And primarily right at the apex of the horseshoe than the ends of it so to speak. 3/4 of the way around the horseshoe you will see a huge rock on the outer edge of the shoreline and in front of that is where it gets deepest. It wont be hard to imagine when you see the slope of the shoreline there, it basically follows down into the pond. When you launch your boat and start heading out there is a huge pad field off to your right, stuck a few frog fish there. Good luck.

d**n I guess I have been doing it wrong haha. I live 5 minutes from here and have spent a lot of time on the water here over the years and never had anything over 3 other than a 17lb carp that I hooked by accident. First time I ever went there after moving into town and I didnt know there were carp in there. For about 30 seconds I thought I was catching the biggest bass I will ever catch for the rest of my life ?? If you dont mind me asking did you catch them in the deep hole or were they cruising the shallows?

What is your definition of close? From the ramp on the Nash to Turkey Pond and Stumpfield Marsh, both in Concord and about 5 minutes from each other, it is 45 min. Both places hold big fish and aren't too big of a body of water. Nothing daunting for kayaking. Everywhere else in the immediate area, Robinson Pond (minnows post above not withstanding ?), horseshoe pond and naticook in Merrimack, are full of small fish. Heald pond in Pepperell, which is pretty small but gets pretty d**n deep for a body of water its size, around 40', has some big fish. I've witnessed boatmates pull out 5'ers a few times and saw a 6+ through the ice there. I pop in there from time to time to mix it up. I once saw a small bird land on a branch of a lay down and a 4+ looking bass launch out of the water to take the bird and branch it was on lol.

You don't want to go to Mill Pond ramp on Google you want to go to the Mines Falls ramp. Its on Stadium drive and when you arrive you stay on Stadium and turn right at the skate park. There is a small sign. It is a nice and fairly new paved ramp. No rocks to speak of in the Nashua in that stretch. When you put in and go upstream you wont encounter any rocks until you pass by a golf course on your left which is a couple miles from the ramp.

Hi everyone! Just stumbled upon this forum and had to sign up and join the community. I have been fishing just over the border in Pepperell and Tyngsboro the last few weeks avoiding my favorite, the Nashua, cause the water level has been so d**n high. We are getting rain tonight but I am sick of holding off any longer!!! Fishing the Nashua end of it tomorrow morning, anyone having any luck this past week in there? I fished the Pepperell/Groton area 2 weekends ago and it was super slow. My biggest fish so far this year in pic. 3.5lb on a hollow body frog bank fishing a dinky pond near my office.