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knormb 05-24-2008 11:34 PM

what size outboard?
My Cal 25-2 currently has a 2 cycle 8hp Johnson outboard motor. It's noisy and unreliable, so I'm thinking that the best long term plan would be to replace it (soon) with a 4 cycle Honda/Yamaha/Nissan or whatever.

2 questions:

Should I stay with 8hp or move up to 9.8/9? The weight seems to be the same, would the speed or fuel efficiency be noticeably different?

Is there a significant difference in quality and longevity between the different brands? I only want to to this once, so a difference in price isn't as important as long term satisfaction.


poopdeckpappy 05-24-2008 11:59 PM

I think rather or not you move up, either size in a new 4s would be more fuel efficient than the 2s.

The question is, do you really need or want to spend the extra money,when it's mostly a kicker motor and 4-5 knots is good enough to motor when needed.

I had a 5hp Merc on a 26' that motored quit well if needed ( 4-5 knots ),.

timebandit 05-25-2008 01:49 AM

Go with the 9.9 and get a mouse ear prop.

artbyjody 05-25-2008 02:34 AM

I picked up a 9.9 Mercury outboard for my C-27. It performed really well, was quiet at lower rpms but a bit noisy at full bore. But in the 6 months I used it never an issue. If looking for a deal on a new but not wanting to pay full price - see if you can purchase the display model. Which is what I did - I negotiated $500 off listed price and still got full warranty etc (West Marine Btw). I had tried to get a Honda but dealerships around here were not easy to find...but in the end I was pretty pleased. Would probably do well for you as there is not too much difference between 25-2 and a 27....

ReefMagnet 05-25-2008 04:48 AM

If, like me, you use your motor to get you home on schedule when the wind dies or is coming in on the nose, I would say go for the 9.9.

I've got a 4 stroke Yamaha 9.9 High Thrust on my 25 footer (about 2200kg). I purchased it second hand (one half of an ex catamaran setup) and have been really happy with it. At the time I was tossing up between the Tohatsu (Nissan), Honda and Yamaha and was actually just about to plonk the money down on a new Yammie when I came across this not too old used one. It replaced an 8 hp two stroke mariner.

A bit of Internet research made me favour the Yamaha High Thrust as it has both a good reputation and is designed especially for displacement speeds - even down to the extra reduction in the gearbox. The Honda has a high thrust prop option, but the gearbox is the same as the standard model. One thing I liked with the Honda is that it retains the pull starter whereas if you get a flat battery with the Yamaha, you have to remove screws to get a rope on the flywheel pulley to start it by hand. The Tohatsus are well priced and light weight but I know of people that have had some issues with corrosion of some mild steel components on them in moored / docked situations

Anyway, love the Yammie. Rarely need to run it at anything past 1/3rd to half throttle to get up to about 5kn+ on my boat, reverse works exceptionally well (something that didn't on the the old Mariner!). I don't normally use the motor in a blow, but I've used it to push against a 4knot current when I've been in a hurry and it'll push the boat well up onto the bow wave at near full throttle.

Fuel usage is about two litres an hour at 5 to 6 knots which is a lot better then the old two stroke it replaced.

SYMandalay 05-25-2008 06:48 AM

Yamaha has the best reputation among cruisers, and the best worldwide distribution. Nissan also makes very good and reliable engines but they are rare in out of the way places. My friends with Hondas complain about them being hard to start and expensive to fix.

Alway choose the biggest engine you and the boat can physically handle, but watch out for the weight of new 4-strokes. They are much heavier than an equivalent 2-stroke.

Quickstep192 05-25-2008 08:29 PM

I would say go with the one that has the best service network available in your area. I swapped an 8hp 2 stroke Yamaha for a 8hp 4 stroke Honda a few years ago. Since then, the local Honda dealer has closed and I find myself having to do my own repairs. I'm OK with that, but my skill level isn't very high. The 4 stroke is definetly more economical on gas. That is slightly offset by the need to do oil changes, but I'll trade that for never having to buy or mess with that stinky 2 stroke oil. My 8hp 4 stroke Honda is quite a bit heavier than the old 2 stroke and makes the boat a little aft heavy, so I had to ballast out the bow. I would imagine that a 9.9 would be heavier yet, but they may have impoved that in the years since I got mine.

knormb 05-26-2008 09:35 AM

Thanks for the advice. I've been looking around and talking to other boat owners in the area, and have just about decided that I'll go with Yamaha. For the same reasons mentioned - a reliable product with good dealer support.

So now the decisions (besides when).

8HP vs 9.9? The 9.9 is only a few pounds heavier and $300 more expensive. So if either one would easily keep the boat at hull speed (if necessary), I'm wondering what the extra power would do for me. Less strain on the engine (longer life)? 20% more engine displacement, would that mean 20% higher fuel consumption?

20" vs. 25" shaft? I'll need to replace my motor mount either way, so which one would you choose? My logic leads me towards the 25", in that the power head and tilt handle would be more accessible. What would be the downside?

Thanks again for the great advice!


Quickstep192 05-26-2008 10:27 AM

According to the Yamaha website, the weight difference is 91lbs versus 83lbs. I suspect the weight difference is mostly that the 9.9 has electric start. A quick check of the Yamaha website shows that the 8hp 2 stroke motor is only 60lbs, so at 83 lbs, you're already adding 23 extra pounds. In my case, that makes the boat heavy in the butt. Electric start might be nice, but I think these motor start pretty easily with the yank start.

feetup 05-26-2008 11:14 AM

8 or 9.9? With the weight being the same, the 9.9 seems the better option. Pounding into chop can be a real Hp. sponge. Just because you have more power available doesn't mean you always have to use it. As far as fuel consumption goes, yes, if you are using all the power you have available you will use more fuel for more Hp. There would be very little difference between the two at a specific speed at or below hull speed, and quite possibly the larger rated motor would give you better economy by being throttled down compared to the smaller rated motor. If you look at a fuel consumption/output graph of most engines you will see a rather sharp rise in consumption as the output gets closer to maximum. I see the T9.9 is 212 cc and the T8 is 197cc. The High Thrust version of the T 9.9 is 232 cc, and one pound heavier than the T9.9. Not a lot of difference, same gear ratios, and only one pound different in weight. Personally I would opt for the 9.9 and discipline myself not to use more power than I need at a given time. Less fuel, longer life, and a reserve of power if you find wind, chop and current against you.

As far as shaft length goes, unless you cannot lift the leg out of the water for some reason, the long shaft is the best option. When motoring ahead of short steep seas, it is not uncommon to have the prop come out of the water, or at least close enough to the surface to cavitate. Conversely, it is not unheard of to drown the power head just after the stern squats into the trough. These are probably the two most common arguments against outboards in the old outboard vs. inboard debate on sub 30 foot boats. The long shaft, run a little deeper than normal helps on both accounts.

As far as price goes, it doesn't really look like an issue.

Around my neck of the woods, most of the fishing guides are going with the Yamaha, and every yacht owner I have talked to about the Yamaha has nothing but good to say. One owner of a 25' has the 9.9 new last year and thinks he might have a bit of overkill, but admits he has never been out in nasty weather where he might need all he can get.

My boat has the outboard waaayyy out there, with a reverse transom, and the electric start/remote is almost essential.


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