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I am in the process if repowering my 1991 17' Boston Whaler Montauk with a new 90 horsepower engine, and I have narrowed my selection down to two choices:

Tohatsu 90 TLDI - what appeals to me most about this engine are the price, the simplicity and hole shot power of a 2 stroke (I previously had a 1991 Yamaha 2 stroke 90 on this boat and loved it), the weight, and the 5 year warranty. I have heard good things about this motor as well. The best quote that I received is $9,200, and this includes controls, a tach, a trim gauge, and a prop (all come standard with a TLDI), as well as rigging and tax (I live in Southern California). The price seems pretty good to me, because I called two other Tohatsu dealers and they were about $1000 higher.

Honda BF90 - what appeals to me about this engine is the Honda name, the 5 year warranty, and the fact that I can get excellent financing on the purchase through Honda Credit (the Tohatsu would be a cash purchase). What I like less about the Honda is the extra weight, and the price, which I was quoted at around $11,400 (this is with controls, prop, gauges, rigging, and tax). I am also thinking that the 2 stroke Tohatsu would pull a skier up quicker than the Honda, but I don't know this for sure. And by the way, I have a 27 gallon Moeller fuel tank (the white one from West Marine) under the pilot seat, and my single batter and switch are under the console.

I am very interested in hearing your opinions about these choices, and if you have any experience with either of these engines mounted on a classic 17' Montauk (especially if you have the Tohatsu - I haven't found anyone yet with this setup, but it seems like a good one for the price).

Thank you all in advance!

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E-TEC 90 is lighter than the Tohatsu and much lighter than the Honda. Three years without any service required, comparable price and if you buy during a promotion you can get the 5 year warranty.

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I own a 8-9 season Tohatsu 90 on my 1977 Outrage 21. I make over 100 trips out of the harbor every season fishing and pulling my Lobster traps. The boat is very waterlogged and is not fast but has been bullet proof.The dealer has not seen the engine since he mounted it . I replaced the water pump impeller once and I just replaced the spark plugs for the second time and replaced the original battery last year. I would not hesitate to buy a 90 Tohatsu for your 17 Whaler. I plan on putting a Tohatsu 115 on my new to me 1989 Outrage 18.

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FYI-Tohastsu makes the smaller engines for a lot of engine manufactures such as Mercury, Evinrude, and I believe Nissan and Coleman. With that said, they must make a good product.

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For a savings of $2200 and the finance charge, I would go with the Tohasu is a second. That is a lot of coin!!!

Sure they are not the "cool" brand. Maybe it's cool to not have the cool brand?

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I have a 2000 Honda BF130 on my 1988 Outrage which replaced the original 150 Merc when my dad had the boat. The weight does cause the splashwell drains to go under when I am standing towards the stern but only by an inch or two. Parts cost more than other brands (I just replaced the power trim/tilt caps and seals which just started leaking oil for $800) however, the reliability and fuel economy are second to none. I run a 12 gallon above deck fuel tank stored under the leaning post (the 63 gallon inboard is empty, clean and dry) so with the economy of the Honda, I do not need as much fuel, I am burning about 1.5 to 2 GPH at moderate cruising speeds and about 3-3.5 GPH wide open reaching top speed of 48mph.
If I was ever to repower, I would consider the E-Tec or another Honda.

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I repowered this year and researched the Tohatsu 90 and was impressed with what I found, I also thought the price was reasonable for a 90 HP. Because I also run a kicker I went with a Yamaha F70 for the lighter weight, but I did get a new Tohatsu 6 HP kicker and I am very happy with both motors. If I were going with a single 90 HP I would feel very comfortable with the Tohatsu 90.

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Just an after thought to my previous post, my old motors had a combined weight of 386 LBS. and my new Yamaha F70 and Tohatsu 6 HP weigh about 320 total. I noticed a BIG improvement in the way the boat ( 1999 Alert 17 ) handles and performs. Weigth wise the Tohatsu is around 337 LBS. which is pretty close to my total weight and the Honda 90 is pretty close to my old motor combination so in my opinion you would be happier with the lighter motor. It's my experience that heavy stern weight affects the performance and handling of the 17 FT hull and the lighter the better. Just my opinion.

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I have a Nissan (Tohatsu) 50hp 2-stroke (pre-TLDI version/carbureted) on my 15. Beautifully made engine and performs outstanding.

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I did a repower last year with a 90hp Tohatsu, and it runs great. Very close in weight to the Etec90 and cost much less. Simple engine, with parts that it looks like you can get to. Little less paint quality than some other but I keep my boat on a trailer. I have 1979 hull and have done a hand full of 80 mile runs and burn about 13 gallons for a trip like one in the video. Check it out. I like the engine a lot.

http://youtu.be/9EzHu7vW5Gs

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Great video Brian. The last time I went under the Golden Gate was on the Enterprise (the carried, not the starship). We had to do it a low tide so the antennas wouldn't hit. Was that a problem for you as well? =8-)

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Although I've heard the 90 Tohatsu TLDI is an excellent engine and the same as Mercury Optimax technology, smaller HP 2-strokes are definitely going away. Besides this Tohatsu you are considering, now only Evinrude is left in the 90 HP 2-stroke market. For better value, and much better resale recognition, you might want to look at Mercury's BRAND NEW 90 4-stroke EFI. It' a whopping 2.1 liter displacement, and should be a real powerhouse at only 359#. This dealer in TN will ship you one in the crate for $7200 + about $200 in shipping and no sales tax. Great deal. Whaler is now installing these on 170 Montauks.

http://www.jacosmarine.com/mercuryeng.../index.cfm

Above, incidentally, someone posted wrong information that Tohatsu makes small outboards for Mercury. Not true.
Mercury and Tohatsu together own a manufacturing Joint Venture and jointly manufacture the 30HP and less engines for themselves. Some of these engines ARE sold to others, such as Evinrude and Nissan. Coleman engines are made in China.

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Evinrude Etec. Say no more.

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No Tohatsu on a BW. It's just not right.

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Nonsense.

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Thank you all very much for taking the time to reply.

I ended up putting a deposit on a new Tohatsu TLDI 90 last week, and the engine should arrive at my boat mechanic's shop for rigging sometime this week. At $9,000 out the door with controls, prop, gauges, cables, oil, etc., the Tohatsu just made the most sense.

I am now trying to decide which gauges to add to the multi-tac and tilt gauges that come with the motor. I am thinking probably an hour meter, and possibly a volt meter and water pressure gauge. I can live without the speedometer, as GPS will provide an indication of how fast I am going if I ever get curious about it.

Another thing I will likely do is add a second battery to the existing setup infer my console. Several mechanics have mentioned that good batteries are critical when running modern direct-injection outboards.

Oh and one more thing I may do is have a new steering box and cable installed. My current steering is pretty good, but it is original to the boat (1991), and a new box and cable on Amazon is not much more than $100.

Am I forgetting anything?

I will let you all know how the engine is once I have some time on the water with it.

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Regarding extra gauges, check out whether your motor can interface with a GPS display. Most modern motors can do so, with the appropriate cabling, and then you can display anything you like.

I have an F70, and the price of connecting the motor to the GPS I already had was quite reasonable.

Tim

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You do not need a second battery. They add complexity, weight, cost and are not necessary unless you are running a bait well etc for hours on end. A properly sized marine battery is sufficient. They are just trying to sell you more stuff.

Make sure the dealer mounts the engine AT LEAST 2 holes up. You will want a stainless prop but it may take a few tries to find the correct size.

Garmin GPS have an option to display voltage, check your unit.

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So I stopped by my dealer today to check on the progress. My old Slozuki had been removed, and my new Tohatsu had just arrived and was still sitting in a box on a pallet. They plan to rig it tomorrow. I am getting pretty excited.

A couple of questions:

1) the dealer forgot to order the digital Tohatsu hour meter that I requested, as well as the water pressure and volt gauges. For the hour meter, if I install it at a later time, will it start from 0 hours, or will it read from the engine's ECU? If. I don't buy the hour meter, how will I know when the motor is ready for its various services?

2) the dealer plans to mount the engine with the cavitation plate even with the bottom of the keel. Is this too low? I hear a lot of talk about mounting it 2 holes up, 3 holes up, etc., but I don't totally get it. I reviewed a diagram on here showing two holes up, etc., but to me, the more holes up (meaning empty holes above the bolt), the lower the cavitation plate would be. Maybe I have this backwards, but I just don't understand I guess. If the dealer mounts the engine at the non-ideal height, how much work is it to change to two holes up, etc.?

FYI, I plan to run the stock Tohatsu aluminum prop for at least the time being, and I will be running the boat mostly in the Pacific Ocean off of Southern California.

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Hi HBeric,
On my new Suzuki I just found out that the oil lamp in the tachometer started blinking when time for oil change/service (20 hours). There are also other lamps indicating (in different combinations) to show how many hours is on the motor but not any exact hours only showing which interval it is, like passes 50 hours, 100 hours and so on.
Might there be a similare system on the Tohatsu?
Check in your instruction manual.

The cavitation plate should be above the keel level, about an inch or more. How much, depends on the propeller. Higher if you have a stainless steel prop.
I think you got it backwards regarding how many holes up.
More holes above the bolts meens that the motor goes up and so the cavitation plate. (the bolts are fixed in height as they sits in the holes in the transom, right...) The holes in the motor bracket moves up with the motor when raising the motor.
Check out two of the last pictures in my personal page where you can see the cavitation plate and the keel relatively.
I have slightly more than an inch above which worked good with the alu prop. I can probably raise more now with my SS prop.
The motor is heavy so you will need a motor lift if you want to raise it later. If the bolts are mounted from the inside (which is the usual) you just remove the nuts.
Lower should be slot holes in the motor bracket so you might not need to remove the nuts completely but losen enought to get clearance for the top bolts to enter next pair of holes in the bracket.
Important, if the bolts moves you will need to reseal them to the transom.

Good luck!

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Failure to mount the engine at the correct and install a correctly sized propeller will lug or over-rev your motor and cause damage.

You want the motor mounted at least two holes up. Could be higher depending on the propeller.

You also want the dealer to install a stainless steel propeller of the correct size and pitch so when the boat is lightly loaded with fuel and gear, it reaches to midrange of the manufacturer's wide open throttle.

You are spending north of $8K, get your money's worth and make sure your dealer does a proper job.

Top set of engine bolts, top of transom looking toward bow
0
0
0 <--- Engine bolt here is 2 holes up
0

The holes in the transom are in standard locations, what hole the bolt uses on the bracket is the variable.

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Thank you both for the mounting information.

So just to be certain, if I mount two holes up and used the standard aluminum propeller for the time being, my boat wont cavitate on tight medium and high speed turns? I want to make sure I have the motor set for optimal handling, quickness to plane, top speed, and fuel efficiency.

The manual says to mount the motor with the cavitation plate even with the bottom of the hull. Do you think mounting engine with this 1 inch higher could void my warranty?

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Cavitation plate 1 inch above keel is no problem at all. 1 1/2 inch should also be ok even with the alu prop. (But you should consider a ss prop if you want better handling)
That should be about two holes up. But it may differ between different brands. My Suzuki is at least 1 inch above the keel with only one hole up. I will probably raise it on more hole when I have time.
Be there when the motor is mounted to be sure it gets on the correct height.

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A few recommendations based on my experience with a Montauk.

If you are planning on using a Tohatsu aluminum propeller (I don't know how good they are in holding)
and for offshore Pacific boating, I would only mount the enigne one bolt hole up. That is per Whaler's specification and will assure you good holding under all conditions. If I was going to run an aluminum prop, I would use a Mercury Black Max/Quicksilver Black Diamond instead (19" pitch will give 42 MPH top end), since I know they hold very well and give great performance for aluminum. Maybe your dealer will substitute one of those for you. Since Mercury and Tohatsu have been working together for years building engines, maybe Tohatsu uses Merc props. I just don't know. I do know that mercury Black Max prop can usually be run 2 holes up also, but individual engine shaft length could be a factor. Some are "taller" than others.

If you want really the best performance from the engine, which has the common 2.33 gear ratio I believe, a Mercury Laser II/Quicksilver Lightspeed prop would do the job, 20" pitch, 45 MPH. They are the best prop you can run on a Montauk period, and better than a Stiletto (which I have also tried - not as good). In this case you would want the engine up two holes, and you will not have any loss of holding. If 20" pitch is too much, the Laser II is also made in 19" pitch, but not the Quicksilver version.
Shipped they are about $350, including hub kit, but check out Ebay for used ones first.

For safest engine installation, and for sound caulking to prevent water intrusion into the lower bolt holes, bolts at the bottom should go in from the outside, and from the inside at the top.

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So the engine is mounted, and now I am just waiting for the binnacle control and a few gauges to arrive. With some luck, I'll have it in the water this weekend.

Regarding how many holes up, I shared what you all recommended, but he mounted it all of the way down anyway. He said that mounted this way, the cavitation plate is about one inch above e bottom of the hull. The engine was tilted, so I couldn't tell for sure, but it did look like it would be about where he said once the engine is down. Also, I noticed a gap between the top of the transom and where the engine would have touched had it been all of the way down. So who know... maybe Tohatsus have shorter lower units.

Either way, it's looking really good, and I can't wait to get it out in the water.

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This is ridiculous.

Ask the mechanic "How many empty bolt holes ABOVE the bolt in the top bracket? If he says 2, you are good. If 1, the motor is mounted TOO LOW.

Not clear?, take a photo showing the back of the transom and motor bracket /bolts, upload it and add a link so we can see.

You are the customer. He should do what you tell him.
You tell him "mount the motor 2 holes up". If it's not that way, he needs to remount the motor at no cost to you.

What is the point of spending time on this board, getting solid knowledge from members and then not following through? It is your $ 8,000.+++ to spend.

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Take a picture showing the vertical distance between the keel and the A/V plate when the plate is parallell to the keel. That is wat's important not how many holes as they may be on slightely different height in the transom on different boats and also the A/V plate may be on different height on different engine brands.

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Just to echo Phil's comments above, when I repowered a couple of years ago, I brought in a lot of printed out research notes from this website to help get the installation correct. A lot of the dealers seem to think that you're telling them how to do their job if you give them input on the installation when really all we want is a proper set up; I thought I was going to end up in a fist fight with their service manager for a few seconds. Fortunately, he started to listen and look at what I was asking for. As the ultimate compliment to the brain trust on this site, he told me at delivery that my boat was the best set up he'd ever seen for a 90 ETEC, everything was dead on to Evinrude's specifications. Good luck, stand your ground and keep your cool, as Phil said above at the end of the day it's your money.