Repower?

Replicant

Steelhead
Does anyone have any experience with repowering a boat? I have an opportunity to assume ownership of a 70s vintage Boston Whaler. Hull is excellent, and while the internal structures (wood seating, steering, etc.) is sound, the engine is the original, under powered Johnson. Still runs, but not my cuppa. Not sure if I should look for a something similar, that is more recent, or put real money into a 'free' boat. I welcome your advice and feedback.
 

Evan B

Bobber Downey Jr.
Staff member
Admin
Definitely. I did a full inboard to outboard conversion with a transom rebuild. Then repowered from the first 150hp Mercury Optimax I put on it to a 225hp Honda four stroke.

What's the boat specs and the current engine?
 

Replicant

Steelhead
Definitely. I did a full inboard to outboard conversion with a transom rebuild. Then repowered from the first 150hp Mercury Optimax I put on it to a 225hp Honda four stroke.

What's the boat specs and the current engine?
It's a 17 foot Boston Whaler, Sportster. Same as the Montauk, but no center console (which I would like to change). Currently has a 70hp Johnson from the mid to late 70s, but rated for 100hp. Not interested in doing any major transom work, but ideally, an engine swap, and a new console.
 

Evan B

Bobber Downey Jr.
Staff member
Admin
Yeah I'd look at any of the modern 70-90HP four strokes. They're all good, honestly. I know Merc has had more duds over the years than the others, but not sure which ones exactly. it'll also depend on if you want to go used or new. Both are going to be hard to get right now.

I think if you went new, the Suzuki DF motors are very tough to beat for bang for buck. Had I not got a screaming deal on a lottery-level lucky find for my Honda BF225, I was prepared to put money down and wait for a new Suzuki.

Suzuki, Honda, Yamaha, Tohatsu, Mercury - if you can find a good deal on any of these, it's hard to go wrong. If you find a specific one you have your eye on, I can help look in to it for you.

Another thing to check is your transom core - when you remove that Johnson, make sure the transom core isn't wet/rotten plywood. If it is, you may need to do transom work whether you want to or not.
 

Chucker

Steelhead
Get the boat checked out by a professional. Old whalers are awesome, until they are not, and then they are most decidedly not.

Repowering an outboard boat is really a no brainer, just pull out all the old stuff, put in the new stuff. If you are going to change to a center console, do it all at the same time as you repower.
 

Replicant

Steelhead
Yeah I'd look at any of the modern 70-90HP four strokes. They're all good, honestly. I know Merc has had more duds over the years than the others, but not sure which ones exactly. it'll also depend on if you want to go used or new. Both are going to be hard to get right now.

I think if you went new, the Suzuki DF motors are very tough to beat for bang for buck. Had I not got a screaming deal on a lottery-level lucky find for my Honda BF225, I was prepared to put money down and wait for a new Suzuki.

Suzuki, Honda, Yamaha, Tohatsu, Mercury - if you can find a good deal on any of these, it's hard to go wrong. If you find a specific one you have your eye on, I can help look in to it for you.

Another thing to check is your transom core - when you remove that Johnson, make sure the transom core isn't wet/rotten plywood. If it is, you may need to do transom work whether you want to or not.
Great information. Thanks! Like I said, hull is in excellent condition. These old whaler's are notorious for being sponges, but the drain ports were sealed a long time ago, along with re-tubed ports.
 

Steve Vaughn

Still learning
Forum Supporter
I don't recall the channel but there is information regarding past issues with various makes and models of outboards and IOs on YouTube. As I recall it seemed to cover larger hp models and was quite detailed. I'm sure a you can find this information with a simple search on YouTube.
 

Chucker

Steelhead
It's a 17 foot Boston Whaler, Sportster. Same as the Montauk, but no center console (which I would like to change). Currently has a 70hp Johnson from the mid to late 70s, but rated for 100hp. Not interested in doing any major transom work, but ideally, an engine swap, and a new console.
Another point - choose your new motor based on its weight, not its horsepower. A 100hp 4 stroke is a much heavier engine than a 70hp 2 stroke. All that extra weight on the back of the boat can really mess things up. You might only be able to put a 60 four stroke on there, but that is probably enough motor anyway, and you’ll be glad of the gas savings!
 

albula

We are all Bozos on this bus
Forum Supporter
I bought a 1987 Whaler Montauk with the original 90 HP Johnson hanging off the back. It ran well enough to take the grandkids crabbing as long as I stayed within rowing distance of the ramp. Beyond that and It might have been a bit sketchy. Recently re-powered with a new 90 Suzuki and should have done it sooner. It opened up a whole new world of possibilities without worry. I had the dealer check all related systems, steering connections etc and now have a boat that perfect for what I do.
 

Jeff Dodd

Steelhead
I think reporting with a new Yamaha would be my choice. As much weight as you can place on the transom. I’d also look for cracks on top of the transom where water may have entered over the years.

I’ve been eying this boat. He doesn’t list the model name though.

 

Replicant

Steelhead
I think reporting with a new Yamaha would be my choice. As much weight as you can place on the transom. I’d also look for cracks on top of the transom where water may have entered over the years.

I’ve been eying this boat. He doesn’t list the model name though.

That's a Montauk. Nice boat, but they're asking too much.
 

Chucker

Steelhead
I think reporting with a new Yamaha would be my choice. As much weight as you can place on the transom. I’d also look for cracks on top of the transom where water may have entered over the years.

I’ve been eying this boat. He doesn’t list the model name though.

Is that really what those are going for now? 20 year old boat for almost $40K. Would have been under 20K two years ago.
 

Replicant

Steelhead
Is that really what those are going for now? 20 year old boat for almost $40K. Would have been under 20K two years ago.
A new Montauk, is around $50k. Shave a few years off of that, and you're in the neighborhood of high $30 to low $40. It seems, that the mid, for a decent boat with a decent motor is in the $20k range, regardless of age. There can be some bargains out there, under that, but they usually need some work. Generally, from what I'm seeing, buyers aren't too concerned with the hull age, when it comes to value, but the motor and goodies, that go with it.
 

albula

We are all Bozos on this bus
Forum Supporter
That's a Montauk. Nice boat, but they're asking too much.
That is the first thing I thought. I purchased my 87 Montauk 17 a couple years ago, granted with an 87 Johnson that I replaced. I paid 12K for the boat and trailer with a Scotty trap puller, radio, electric motor, Bimini top and 9 hp kicker. If this CL ad is any indication it appears my boat was a great investment.
 

Jeff Dodd

Steelhead
That is the first thing I thought. I purchased my 87 Montauk 17 a couple years ago, granted with an 87 Johnson that I replaced. I paid 12K for the boat and trailer with a Scotty trap puller, radio, electric motor, Bimini top and 9 hp kicker. If this CL ad is any indication it appears my boat was a great investment.

Newer is not always better (for Whalers) I understand.
 

Jeff Dodd

Steelhead
Is that really what those are going for now? 20 year old boat for almost $40K. Would have been under 20K two years ago.

A new Yamaha 90 is $11K, plus tax and installation.

I think this boat is overpriced but the right vintage Whaler hull is worth more to me than a newer model.
 
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