Repower knowledge base

[HalfCaff]

I know there are about 1 million threads on here already about repowering this boat or that boat, and they are a wealth of info but quite a bit to sift through.  I thought it might be a good idea to start a "knowledge base" style thread to collect general well earned wisdom, advice, lessons etc. about repowering our boats.

As I have mentioned on other threads, I am probably due for a repower within the next couple seasons.  I have a 1987 Sea Ranger 17', and the main is a Honda 75hp 4 stroke, dated to approximately '97 by the serial numbers, and over 3500 hours if my hour meter is to be believed.  It has given me no real issues thus far (knock on wood), other than a prop strike last season.  It takes a little finesse on the choke to get it going when cold, but I can usually do it on the first turn of the key - second at best.  All that said, I haven't taken it for any truly long runs over 30 mins max.  I usually run out to the fishing grounds and troll on my kicker.  I know these motors have a good rep for longevity when taken care of, and this one has been.  Same mechanic for the last 15+ years, all receipts etc.  Still, I'm resigned to the fact that it is only a matter of time and it sure would be nice to not deal with a carburetor and choke anymore.  And as I take my boat further afield and away from civilization for some cruising, I just am always sort of waiting for the shoe to drop, so to speak.

So all that said, I can contribute more questions than answers regarding repowering at this point, so I'll kick off the discussion that way?  Not really expecting answers to all of these questions, they are just jumping off points for the discussion.  Feel free to contribute whatever you think is relevant.

1) What criteria do you use to decide it is time?  Hours, maintenance costs, age, run it until it dies?

2) When you last repowered, what did you start with and what did you go to?  Do you have a particular allegiance to specific brands or models?

3) Budget, if you are comfortable sharing

4) What did you do yourself versus what you paid someone else to do?

5) What would you do different next time?

6) What caught you by surprise?

7) Is there anything specific to know about repowering an Arima versus any other boat?

[davidsea]

  The perfect time to repower is JUST before the engine dies, and if you're able to predict that, you could make lots of money as a fortuneteller - or stock trader.
   Seriously, it's usually a matter of your comfort zone.  If you're going offshore for tuna, it's a lot more stressful than lake fishing.  If your kicker is newer and 100% reliable, it's less stressful, but if you're running the kicker off the same fuel supply as the main, not so much.  I feel that a really solid VHF/antenna and GPS are requirements for the salt - cellphones and handhelds don't get it.
   I bought my 19 well-used, with a carbureted and pre-nmea Honda 75 with unknown hours, knowing that the motor was both too small and too old for my use. The dealer agreed to buy back the 75 and sell me a new BF115.  He was very accommodating, giving me a fair trade and some discounts on controls, cables and rigging parts.  I showed up with all the original motor rigging and controls removed. They pulled the old motor, dropped on the new one, and I was gone in an hour, smiling all the way home.  Motor budget was around 10.5K less trade-in.
  I wanted a Honda, based on previous experience with 2 others, and I think the 115 is the best performing motor in its class, ideal for my 19 Hdtp.  After 3 years, I haven't changed my opinion.   I did all the work myself, spending about 9 months replacing electrical, fuel, steering - basically everything attached to the boat is new except the fuel tank.  I did NOT count hours,  quit counting dollars about halfway through, and would be embarrassed with the total if I knew.  The upside is that I know exactly where everything is, what it does, and how to fix it if it breaks.
   I was surprised by how long it took and how much it cost, but it was still much cheaper than buying a new rig - and everything is just how I want it.  I think a good formula to go by is that it will likely cost half-again as much and take twice as long as you think, but I wouldn't do it differently.
   Repowering an Arima is pretty normal as long as you remember that they are short, wide, and heavy. They have the ability to carry a LOT of weight, so most owners do just that.  Underpowering won't save you much on fuel, is harder on the motor, and will make the boat less responsive when you need it.  Don't skimp on horsepower to save a few dollars.                 (I'm the exception here, so my opinion is just that.)                            

[DARice]

There are many different reasons to repower. I added a new kicker because the one that came with the boat was DOA. The main was a very different decision.

My quick summary on replacing the main:
-Reliability/confidence for my use
-How long I intend to keep the boat
-Ease of maintenance, including part availability
-Value of the old/outgoing motor that would decline rapidly

It was a low hours Mercury 4 stroke (2004, when I sold, 400hrs). I had some troubles with that motor--the solutions were inexpensive and completely effective--but I lost most of a summer diagnosing it myself and paying mechanics (my solution was what worked), then rebuilding my confidence in the motor to go offshore.

Parts were very hard to find and the specter of a 'someday' very expensive carb rebuild and some heavy corrosion on the steering arm gave me pause for how I mostly use the boat:  solo in the ocean.

When decided that the SC17 is really the right boat for me for the foreseeable future, in spite of periodically straining against 2 footitis (symptoms are abating!), I chose to sell the Mercury while it still had great value and start enjoying a new motor right away. I'm extremely happy with my decision.

Dave

[HalfCaff]

The perfect time to repower is JUST before the engine dies, and if you're able to predict that, you could make lots of money as a fortuneteller - or stock trader.
   Seriously, its usually a matter of your comfort zone.  If you're going offshore for tuna, it's a lot more stressful than lake fishing.  If your kicker is newer and 100% reliable, it's less stressful, but if you're running the kicker off the same fuel supply as the main, not so much.  I feel that a really solid VHF/antenna and GPS are requirements for the salt - cellphones and handhelds don't get it.
   I bought my 19 well-used, with a carbureted and pre-nmea Honda 75 with unknown hours, knowing that the motor was both too small and too old for my use. The dealer agreed to buy back the 75 and sell me a new BF115.  He was very accommodating, giving me a fair trade and some discounts on controls, cables and rigging parts.  I showed up with all the original motor rigging and controls removed. They pulled the old motor, dropped on the new one, and I was gone in an hour, smiling all the way home.  Motor budget was around 10.5K less trade-in.
  I wanted a Honda, based on previous experience with 2 others, and I think the 115 is the best performing motor in its class, ideal for my 19 Hdtp.  After 3 years, I haven't changed my opinion.   I did all the work myself, spending about 9 months replacing electrical, fuel, steering - basically everything attached to the boat is new except the fuel tank.  I did NOT count hours, and quit counting dollars about halfway through, and would be embarrassed with the total if I knew.  The upside is that I know exactly where everything is, what it does, and how to fix it if it breaks.
   I was surprised by how long it took and how much it cost, but it was still much cheaper than buying a new rig - and everything is just how I want it.  I think a good formula to go by is that it will likely cost half-again as much and take twice as long as you think, but I wouldn't do it differently.
   Repowering an Arima is pretty normal as long as you remember that they are short, wide, and heavy. They have the ability to carry a LOT of weight, so most owners do just that.  Underpowering won't save you much on fuel, is harder on the motor, and will make the boat less responsive when you need it.  Don't skimp on horsepower to save a few dollars.                 (I'm the exception here, so my opinion is just that.)                            

Good take/info.  I have put a lot of sweat equity into my boat already since buying last year. Pretty much a full rewire minus the motor controls and gauges. Mounted riggers, trim tabs, move ducer, fixed splashwell drain tube, new bilge pump with enlarged access, mounted new Merc 9.9 kicker on fixed bracket.  I think I could probably hand pulling the old controls off the boat and installing the new controls and gauges.  Would most likely leave the actual hanging of the motor to a pro.

I hear you on error on the side of more power not less, but also thinking about weight.  I think a new 90hp would weigh around the same as the 75hp I have on there now.  Weight wise it is tempting to look at a Yamaha F70 and I know there is at least one member here with that combo I'd love to hear from, but it seems the overwhelming majority consider 90hp the min for a SR17.

Safety wise I have no ambitions to chase tuna off shore, but would like to work the west cost of Vancouver Island for Salmon.  The vast majority of my fishing is a 45 min run max, with lots of other boats around.  But we may explore the Broughtons or some other longer runs this year.  Safety wise of course all the mandatory gear, as well as a new VHF with DSC and antennae, GPS was already on it and we have a Garmin Inreach on board as well. PFD always, no exceptions.  Likely will invest in a handheld VHF for backup and an personal locator beacon too.

[HalfCaff]

There are many different reasons to repower. I added a new kicker because the one that came with the boat was DOA. The main was a very different decision.

My quick summary on replacing the main:
-Reliability/confidence for my use
-How long I intend to keep the boat
-Ease of maintenance, including part availability
-Value of the old/outgoing motor that would decline rapidly

It was a low hours Mercury 4 stroke (2004, when I sold, 400hrs). I had some troubles with that motor--the solutions were inexpensive and completely effective--but I lost most of a summer diagnosing it myself and paying mechanics (my solution was what worked), then rebuilding my confidence in the motor to go offshore.

Parts were very hard to find and the specter of a 'someday' very expensive carb rebuild and some heavy corrosion on the steering arm gave me pause for how I mostly use the boat:  solo in the ocean.

When decided that the SC17 is really the right boat for me for the foreseeable future, in spite of periodically straining against 2 footitis (symptoms are abating!), I chose to sell the Mercury while it still had great value and start enjoying a new motor right away. I'm extremely happy with my decision.

Dave

Good take as well - considering how long you might keep the boat is a good criteria.  In my case, this is probably my boat for at least the next 10 years.  I have a bit of a challenging uphill driveway and my boat shelter just fits it.  I don't physically have room for a bigger boat.  In my case, two-foot-itus would mean either getting moorage (which isn't cheap or easy to come by), or a bigger house/property.  Plus, 75% of the time I fish solo and if not it is the wife or maybe 2 other guys.  The SR17 is probably the perfect size boat for where I am at now - mostly inshore fishing with the odd trip further afield when weather allows.  Easy to trailer on Vancouver Island where I live, so I can explore all of the different spots that are a reasonable drive away.  The only reason I would see trading up soon is if something catastrophic happened.  Give me 10 years when I am ready to retire to the North Island, I'll probably want something a little bigger by then.

[fishmeister]

My choice to re-power was due to problems starting to creep up with my main.  I was feeling like I was starting to dump money into it.  I was also starting to question reliability, which caused me to limit my range from the launch. My main was a '96 that was on the boat when I bought it (PO hadn't owned the boat very long so history was a big, fat, unknown).  The hour meter said over 1400hrs.  But, I had a suspicion that the controls/gauges might have been re-used from the last re-power.  Therefore, I had no way to authenticate the hours.  When I had a carb problem and the culprit was the one (of four) that was obsolete and could not be found anywhere, decisions had to be made (a sudden, unexplained oil leak kind of helped decide too).

I had to decide if I wanted to spend the money to drop a new motor onto a then-41yr-old hull (I'm sure that some folks here think I'm crazy for that).  Like DARice, my long-range plans for the boat was a huge factor.  I love my little SH.  I had already poured quite a bit of money into it and I knew that I wanted to keep it for the long-haul.  I do a mix of fishing.  Lakes, river, and Puget Sound.  The SH is good at all 3 and is a really versatile boat.

I had other decisions to make too.  I had to decide used vs. new.  I also had to decide whether to try and re-use the rigging, controls, gauges.

Both of these choices also came down to long-range plans for the boat.  I didn't have the cash for a re-power laying around.  So, financing was going to have to happen (regrettably).  I wasn't going to run the risks of getting a used motor only to have to repeat this four or five years later.  I decided that, if I'm going into debt for this, I'm going all-in and only going to do it once.  I decided that I was going to go all-new-everything.  I wasn't willing to go that far in, cheap-out somewhere, and then have to continue to dump more money into the motor/running gear.

I don't regret any of the choices.  I've got a new motor, new controls/cables, and a new digital gauge.  I can now rely on that motor.  I really enjoyed feeling comfortable taking it for longer runs last summer to slay some humpies (and a coho).  I now have a motor for which I know the hours and all maintenance history.  I just fired it up for the first time of the year a couple weeks ago.  Previous startup was Thanksgiving weekend last fall.  The motor fired up as if I had just run it the day before.  It's hard to beat that feeling.

My re-power came during the later stages of the Covid panic.  Availability really sucked.  My choice of motor brand was driven a lot by the fact that I stumbled onto a small local dealer that had the right size motor sitting on his showroom floor due to a cancelled job.  Some places were telling me to expect a 6-9 month wait for a motor to come available.  I didn't want to miss the entire fishing season so I took the motor that was available.

When all was said and done, I was in to my re-power for about $10.5K.  That was new-everything (motor, wire harness, control, shift/throttle cables, and gauge).  I did save some money working with a small, local shop (shout-out to Salish Boat Co.).  He was great to work with.  He had no problem providing me with a parts list and I shopped for the rigging online myself.  I did all of the prep work.  I had the old motor removed, all old rigging removed, and the gas tank pulled.  I also took care of filling some old mount holes that I found on the transom.  I took care of the final dash repair/overlay to mount my gauge.

In the end, I really have no regrets about my choices and how it turned out.  I'm really enjoying my boat now.

That's my story.

[HalfCaff]

My choice to re-power was due to problems starting to creep up with my main.  I was feeling like I was starting to dump money into it.  I was also starting to question reliability, which caused me to limit my range from the launch. My main was a '96 that was on the boat when I bought it (PO hadn't owned the boat very long so history was a big, fat, unknown).  The hour meter said over 1400hrs.  But, I had a suspicion that the controls/gauges might have been re-used from the last re-power.  Therefore, I had no way to authenticate the hours.  When I had a carb problem and the culprit was the one (of four) that was obsolete and could not be found anywhere, decisions had to be made (a sudden, unexplained oil leak kind of helped decide too).

I had to decide if I wanted to spend the money to drop a new motor onto a then-41yr-old hull (I'm sure that some folks here think I'm crazy for that).  Like DARice, my long-range plans for the boat was a huge factor.  I love my little SH.  I had already poured quite a bit of money into it and I knew that I wanted to keep it for the long-haul.  I do a mix of fishing.  Lakes, river, and Puget Sound.  The SH is good at all 3 and is a really versatile boat.

I had other decisions to make too.  I had to decide used vs. new.  I also had to decide whether to try and re-use the rigging, controls, gauges.

Both of these choices also came down to long-range plans for the boat.  I didn't have the cash for a re-power laying around.  So, financing was going to have to happen (regrettably).  I wasn't going to run the risks of getting a used motor only to have to repeat this four or five years later.  I decided that, if I'm going into debt for this, I'm going all-in and only going to do it once.  I decided that I was going to go all-new-everything.  I wasn't willing to go that far in, cheap-out somewhere, and then have to continue to dump more money into the motor/running gear.

I don't regret any of the choices.  I've got a new motor, new controls/cables, and a new digital gauge.  I can now rely on that motor.  I really enjoyed feeling comfortable taking it for longer runs last summer to slay some humpies (and a coho).  I now have a motor for which I know the hours and all maintenance history.  I just fired it up for the first time of the year a couple weeks ago.  Previous startup was Thanksgiving weekend last fall.  The motor fired up as if I had just run it the day before.  It's hard to beat that feeling.

My re-power came during the later stages of the Covid panic.  Availability really sucked.  My choice of motor brand was driven a lot by the fact that I stumbled onto a small local dealer that had the right size motor sitting on his showroom floor due to a cancelled job.  Some places were telling me to expect a 6-9 month wait for a motor to come available.  I didn't want to miss the entire fishing season so I took the motor that was available.

When all was said and done, I was in to my re-power for about $10.5K.  That was new-everything (motor, wire harness, control, shift/throttle cables, and gauge).  I did save some money working with a small, local shop (shout-out to Salish Boat Co.).  He was great to work with.  He had no problem providing me with a parts list and I shopped for the rigging online myself.  I did all of the prep work.  I had the old motor removed, all old rigging removed, and the gas tank pulled.  I also took care of filling some old mount holes that I found on the transom.  I took care of the final dash repair/overlay to mount my gauge.

In the end, I really have no regrets about my choices and how it turned out.  I'm really enjoying my boat now.

That's my story.

Its a good story too!  $10.5K for all new, installed seems like a good deal to me, even if you did a lot of the prep work and rigging yourself.  If I follow the same path, I'll be paying in Canadian funny money, so I don't think it works out quite so well for us.  Is what it is though.  I did get a good deal on my kicker last year I think, and rigged that myself.  Even unloaded it from the back of the pickup myself... which was a bit of a trick!

[davidsea]

Weight wise it is tempting to look at a Yamaha F70 and I know there is at least one member here with that combo I'd love to hear from, but it seems the overwhelming majority consider 90hp the min for a SR17.

Consider more than just one number (horsepower) when you're looking at engines.  In the Yamaha line, the F50/60/70 are all the same displacement and weight.  Personally, I don't think a 1-liter motor with a 15A alternator is going to be enough for a 17' fishboat. The F75/90 are 100# heavier, but are 1.8 liters with 35A alternators.  Honda BF75/90/100's are all 1.5L, 35A, 6# heavier than Yamaha.  Displacement - and torque numbers, if you can find them - are more important than horsepower on our heavier, slower Arimas.  A healthy alternator output is always a good thing on a well-equipped boat.

[HalfCaff]

Weight wise it is tempting to look at a Yamaha F70 and I know there is at least one member here with that combo I'd love to hear from, but it seems the overwhelming majority consider 90hp the min for a SR17.

Consider more than just one number (horsepower) when you're looking at engines.  In the Yamaha line, the F50/60/70 are all the same displacement and weight.  Personally, I don't think a 1-liter motor with a 15A alternator is going to be enough for a 17' fishboat. The F75/90 are 100# heavier, but are 1.8 liters with 35A alternators.  Honda BF75/90/100's are all 1.5L, 35A, 6# heavier than Yamaha.  Displacement - and torque numbers, if you can find them - are more important than horsepower on our heavier, slower Arimas.  A healthy alternator output is always a good thing on a well-equipped boat.

Oh for sure, never underestimate my capacity for compulsive research before making a major purchase.  You should see the spreadsheet I made before I settled on a kicker! Writing and reviewing RFP's is a big part of my day job too. All the key specs would be lined up side by side, and lowest price wouldn't necessarily be the final choice.

[fishmeister]

If I follow the same path, I'll be paying in Canadian funny money, so I don't think it works out quite so well for us.

Yeah, paying in Loonies and Toonies is likely to add a bit to the cost, regardless of which brand you go with.  Maybe you can hook up the boat and "make a run for the border"?  Bring it down here for the swap?  Not sure if that's worth the savings.   

[HalfCaff]

If I follow the same path, I'll be paying in Canadian funny money, so I don't think it works out quite so well for us.

Yeah, paying in Loonies and Toonies is likely to add a bit to the cost, regardless of which brand you go with.  Maybe you can hook up the boat and "make a run for the border"?  Bring it down here for the swap?  Not sure if that's worth the savings.   

Pretty sure they'd get me at the border with taxes and duties, and my money is only worth 73 cents on the greenback, as of today. 

[headduck]

I repowered with a consideration of 2 footitis. Went with a 115 on a 17, then transferred to 19. Went with merc, it was a cost thing, saving a couple grand over the next cheapest, Yamaha.

Original johnson was neglected and becoming ever more unreliable and dangerous.

Removed the original with help of a gent who wanted to purchase it from craigslist.

Shop mounted the new and they ran all new controls. Purchased warranty from another shop at ½ the cost.

On the 19 swap. I swapped the controls while the shop did the heavy lifting. One lesson was to be sure the steering tube is connected at time of motor install otherwise clearance is a challenge.

[JDB]

A couple of months ago did a repower (21 foot SR skip) from an old but very low hour/lot of time sitting in saltwater Suzuki df140 (first Gen 2.38:1) to a Merc 150 (MASSIVE torque difference).  Has Salish Boat Co. do the big work, did the rest at home.  (Great peop's at Salish in Anacortes).  Wasn't confident in the reliability of the old previously neglected motor; swapped it out before it seriously stranded us out on the water.  Definitely work on engine height with a sea trial.

Also took the time to replace bilge hoses, reroute electrical harness, clean fuel tanks, replace fuel lines, relocate fuel water separator...
Now have much more confidence in the reliability. 

No idea how much I spent, the price is worth the satisfaction and enjoyment.

[HalfCaff]

Thanks for the comments and adding to the discussion folks.  Good tip on the steering tube head duck.  I think I almost have my wife convinced to at least start getting some quotes together.  I am in the process of selling a camper van we built during peak covid and before I bought the boat, so will hopefully get some scratch toward the cause from that. 

I hear often people saying something to the effect of "engine needs to go up a hole".  I assume that is basically redoing the mounting - ie pulling the gas tank, pulling the bolts, having a hoist, resealing the through holes etc.  Seems it would be in the best interest to do everything you can to get it at the right height to start with, but maybe I don't fully understand the process.

What did everyone do about their steering when they repowered?  Keep the mechanical steering or did anyone switch over to hydraulic in the process?

[JDB]

What did everyone do about their steering when they repowered?  Keep the mechanical steering or did anyone switch over to hydraulic in the process?

Switched from no feedback rack and pinion to Hydraulic (Uflex).  Very nice upgrade especially considering the HP/torque difference.

I'm sure Tom C. has more extensive knowledge of motor mounting heights, but I'm trying to get the anti-ventilation plate just at the surface (getting spray is okay) of the water when at cruise...  Which is similar to what the Suzuki was set up like.  Little less drag (better fuel efficiency), little less steering effort, but the potential to have ventilation and porpoise issues (both bad).

[fishmeister]

What did everyone do about their steering when they repowered?  Keep the mechanical steering or did anyone switch over to hydraulic in the process?

My boat had hydraulic (Baystar) when I bought it.  So, I kept the steering "as is".  Granted, I don't have any experience for comparison.  But, I do like the feel and control when running in currents such as Deception Pass and the Skagit River.

[Tom C]

All modern outboard motors over ~>50 HP and <300 HP are mounted to the boat with four bolts that are spaced according to an industry standard, known as the BIA bolt pattern, which has its origin all the way back in 1960 when OMC introduced the first V-4 outboard. It became standard in the industry in the mid 1980s.

Arimas have all been built during this period of standardization, so virtually all outboards used on Arimas can be adjusted vertically on the transom with relative ease.

All large outboards have mytiple mounting holes to allow this. The spacing on center (o.c.) between adjacent holes is 3/4" (sometimes described in millimeters for Hondas, but it's the same distance)

Most outboards used to power Arimas have four or five sets of mounting holes, so there is a good range of choice. When describing mounting height, the most common jargon is how many "holes up". This is sometimes confusing to some folks, so here is the pictograph I use where the lowercase letter "o" represents a mounting hole in the motor's bracket where the bolt goes through:

o <— mounted all the way down (on the transom)
o <— mounted one hole up
o <— mounted two holes up
o <— mounted three holes up
o <— mounted four holes up

Yamaha describes the holes in terms of position where the top hole (lowest mounting) is position #1, and so on.

[Tom C]

All that said, the mounting position will depend on the motor chosen.

The goal is always the same, achieve the best possible performance from the new motor, however, the definition of "performance" is up to you. For one person it might be best fuel economy, for another it might be handling, yet another might want the best top speed. Those goals are not necessary mutually exclusive, but there are some trade-offs.

Motor mounting height also depends, to some degree, on the propeller being used; some props will not tolerate high mounting positions.

As a starting point, the cavitation plate (AV plate) of the motor should not be lower than the keel of the hull when the motor is trimmed so the cavitation plate is a parallel to the keel.

For most small boats in this class, I recommend the cavitation plate be 1/2" to 1" ABOVE the keel.

[Tom C]

Most vintage Arimas had their original motors mounted all the way down. They used mechanical steering, and the splashwell cut-out and boot for the steering cable was positioned for this.

You can repower and raise the motor one hole and still use the boot (on my 17SR, just barely) but once you're two holes up, you either elongate the hole, fill and re-drill the hole...or switch to hydraulic.

For small motors, a new mechanical steering system is great, reliable and inexpensive (~$300), but hydraulic is a step up and solves some problems. But it is also expensive. You're not going to get a new hydraulic system for less than ~$1,000 all in.

[fishmeister]

Most vintage Arimas had their original motors mounted all the way down. They used mechanical steering, and the splashwell cut-out and boot for the steering cable was positioned for this.

You can repower and raise the motor one hole and still use the boot (on my 17SR, just barely) but once you're two holes up, you either elongate the hole, fill and re-drill the hole...or switch to hydraulic.

For small motors, a new mechanical steering system is great, reliable and inexpensive (~$300), but hydraulic is a step up and solves some problems. But it is also expensive. You're not going to get a new hydraulic system for less than ~$1,000 all in.

And then there are real "vintage" Arimas, like mine.

My '81 seems to pre-date standardization.  I'm sure that the original motor was probably around a 45hp 2-stroke.  When I removed my old motor, I found old, siliconed, mount holes that were small and nothing close to modern layout/spread (I drilled out the silicone and glassed them in).  I also found two distinctive round clamp marks on the inside of the transom.

The motor that I removed was a '96 Merc 4-stroke.  It only had 3 sets of holes.  Some joker mounted it by drilling the top set of holes for the top and the bottom set of holes on the lower.  That would have made adjusting up/down impossible.  I also glassed in those lower holes.  I had my new main installed with properly drilled holes.  My new Merc has 5 sets of holes, like TomC's diagram.

[HalfCaff]

Thanks for the great info Tom C.  What do you figure is the ideal HP/displacement for a SR17, used primarily in the salt.  Not really going offshore, but will do some cruising and overnighting in the Broughtons, or some of the sounds on WCVI.  My priority wouldn't be top speed, but safety and reliability, I guess followed by gas mileage.  Weight matters too but seems like most motors with comparable HP are also within the same weight range, give or take.

[Tom C]

90 HP which will push the boat to 35 MPH. Not much fun going faster than that. I have a Yamaha F70 on mine, and it can hit 30 MPH and sips fuel. Might not be great loaded with a family and camping gear, but that's not how I use it.

The light weight of the F70 has a remarkable effect on the buoyancy of the hull. I removed the T9.9 and its bracket, lightening the load even more. The Yamaha's can be fitted with the troll control switch to toggle down the idle speed for trolling.

[HalfCaff]

Thanks again Tom C.  Yes, I noted with interest when you mentioned your F70 on a SR17 in another thread.  I've got the impression in my short time here that you seem to be one of the more respected/go to sources of information when it comes to the things that actually move our boats - motors and props.  So when I saw you had gone with the F70, I figured there must be a reason - weight being the obvious one.  I also note though that your response to my question about "ideal" motor size for a SR17 is aligned with the vast majority of opinions I have seen - 90hp.  I guess maybe it is a specific scenario and style of intended use that makes the F70 an option for you?

I admit that the weight advantage is compelling to me.  If I went with a smaller engine it wouldn't be to save money, it would be to save weight.  I haven't been able to definitively search out an online weight spec for my existing 1997 Honda BF75 - but current models there isn't really a difference in weight between the 75 and the 90.  So I am reasonably confident that I at least wouldn't be GAINING weight going up to a 90, but can't say that for certain.  As it is, I do suffer from the Arima butt heavy syndrome.  With the 75hp, the dual batteries, Merc 9.9 EFI, and 3/4 tank fuel at rest my splash well drain tube sits just at or just under the water line.  And it doesn't take much of a following see to have water come over the lip of the splash well.  I realize a splash well is meant to be wet, but I'd like to have a little more room for error if I can get it.  Perhaps I should have forgone the extra weight of the EFI and gone with a carbed kicker - I think that was about 30lbs or so if I recall.  I do keep my front water tank full, and carry my tackle and downrigger weights forward in the cuddy.

So yes, definitely intrigued by the lower weight of the F70, if it could be made to work.  I don't have a big family - just the wife and I and one dog sometimes.  We wouldn't be carrying tonnes of gear or going for long hauls camping, just overnight or maybe a weekend, and we're generally pretty light packers.  I would say 60% of my boat use is just me fishing solo, and in that case I'm just carrying tackle and gear for a day trip.  I don't even usually bring a cooler of ice – just a kill bag.  The other 30% might have two of us on board doing the same thing, and maybe 10% tops would we have 3 people on board or extra gear for camping.  Safety is always a primary consideration.  I don't intentionally go out in too bad of a sea state, but of course wouldn't want to find myself in a situation where I got caught off guard and didn't have the power to navigate properly back to calmer waters.

I'll admit I haven't spent too much time at WOT with my 75hp, but it cruises with a regular day trip load and two people at about 23-24mph, 4000 RPM or so.  I just have the old analog tach so not sure how accurate it is to be honest.  Since I added my trim tabs I only have one day on the water, and it was pretty calm.  Seemed like I could hold plane down to about 3200 rpm or so in those conditions, with some tab.  Still learning how to use them of course.  Would it be reasonable to expect similar performance from an F70, propped efficiently and mounted correctly?  Especially given the overall weight would be a little less with the lighter motor?

[Tom C]

I haven't been able to definitively search out an online weight spec for my existing 1997 Honda BF75

The 1997 Honda BF75 weighs either 383 or 394 pounds, depending on the shaft length.

A new Yamaha F70 weighs 253 pounds.

[HalfCaff]

I haven't been able to definitively search out an online weight spec for my existing 1997 Honda BF75

The 1997 Honda BF75 weighs either 383 or 394 pounds, depending on the shaft length.

A new Yamaha F70 weighs 253 pounds.

Thanks Tom C.  Sounds like even if I go for a 90hp I would stand to lose about 30 pounds give or take, if that's the case.  Good to know.  Now it is a matter of prioritizing weight vs power I guess.