Is a Honda 9.9 really a 15 HP ?

Dean Youngquist

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Mar 24, 1993, 3:32:25 AM3/24/93

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I was looking at Honda outboards yesterday and noticed that the 9.9 HP model
seems identical to the 15 HP model except that the 9.9 has an extra bolt in
the throttle linkage which prevents it from opening completely. The gear
reduction ratio is the same on both motors, also stroke, bore, and propeller.

Could I just remove this bolt and have a 15 HP for the price of a 9.9 ?

Dean Youngquist youn...@ucs.orst.edu
428 NW 9th Street, Corvallis, OR 97330
Phone & fax (503) 758-6230 anytime

Wallace Venable

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Mar 25, 1993, 4:43:22 PM3/25/93

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> I was looking at Honda outboards yesterday and noticed that the 9.9 HP model
> seems identical to the 15 HP model except that the 9.9 has an extra bolt in
> the throttle linkage which prevents it from opening completely. The gear
> reduction ratio is the same on both motors, also stroke, bore, and propeller.

> Could I just remove this bolt and have a 15 HP for the price of a 9.9 ?

>Yes, I believe you are right. 10 (or 20) HP is the lower limit
>for registration of motorboats in many countries. So, the
>manufacturers make different models to fit these limits.
>It is much cheaper to cripple a 15 HP engine to <10 HP than to
>make both 10 and 15 HP ones, so...

In the US, we have many lakes with MAXIMUM allowable horsepower.
The 9.9 is "less than 10 HP," even if it is alomst the same as a 15.

BR McCall

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Mar 25, 1993, 6:49:17 PM3/25/93

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In <JUSSI.93M...@tor.abo.fi> ju...@tor.abo.fi writes:

>>
>
> Yes, I believe you are right. 10 (or 20) HP is the lower limit
> for registration of motorboats in many countries. So, the
> manufacturers make different models to fit these limits.
> It is much cheaper to cripple a 15 HP engine to <10 HP than to
> make both 10 and 15 HP ones, so...
>

> jussi
> --
> Jussi Laaksonen
> Computing Centre / ]bo Akademi University, Finland
>

I was told by a local sales dealer for Nissan motors that for an extra $50
he could sell me a 9.9 and make it into a 15 HP motor. Is it just as easy as
pulling out a bolt? I tend to be untrusting of salesmen who say they can work
wonders for a little extra money, espesally being in backwoods Arkansas. I
would love to hear more about this subject!
Also, slightly off the subject, how dose Honda compare to Niassan? And how
do the two compare to other outboard moters in the 9.9/15 HP class as far as
dependability, duribility, price, resale value, speed, hole shot, ect.?
A mechanics comments would be nice, but all are more than welcome, facts or
opinion!

answer to e-mail:

BRMC...@ACS.HARDING.EDU
OR post to the board, I think this might be of intrest to many.

(For what it is worth, I am new to the vax, so please forgive any blatent
mistakes or flagrent violation of vax manners)

Brian Smith

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Mar 29, 1993, 2:29:52 PM3/29/93

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In rec.boats, BRMC...@acs.harding.edu (BR McCall) writes:

Also, slightly off the subject, how dose Honda compare to Niassan? And how
do the two compare to other outboard moters in the 9.9/15 HP class as far as
dependability, duribility, price, resale value, speed, hole shot, ect.?

Not a mechanic, so I can't help you there. I looked last year for a
small engine for my sailboat (not an easy task in Colorado). I came
to the conclusion that, in the 15hp and below range, all Nissans are
2-strokes, all Hondas are 4-strokes, and all Yamahas are twice as
expensive (I could be wrong, of course).

I wanted a 4-stroke so I went with a Honda. Hope to try it out for
the first time next weekend.

B.S!

Kevin Ormerod

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Mar 29, 1993, 10:27:45 AM3/29/93

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>I was told by a local sales dealer for Nissan motors that for an extra $50
>he could sell me a 9.9 and make it into a 15 HP motor. Is it just as easy as
>pulling out a bolt? I tend to be untrusting of salesmen who say they can work
>wonders for a little extra money, espesally being in backwoods Arkansas. I
>would love to hear more about this subject!
> Also, slightly off the subject, how dose Honda compare to Niassan? And how
>do the two compare to other outboard moters in the 9.9/15 HP class as far as
>dependability, duribility, price, resale value, speed, hole shot, ect.?
> A mechanics comments would be nice, but all are more than welcome, facts or
>opinion!
>

My advise would be to get your hands on the parts manuals for these motors
and make some comparisons.

Mercury's new lineup of V6's consists of a 2.5 litre 150, 175, and 200 Hp
versions. I have looked at the parts manual and the major difference is
the inside of the crankcase. The is a separate crankcase for the 150, the
175, and the 200. However, on the outside you can't tell them apart. I
thought I'd only have to change the electronic module, but not so. I
suspect the differences are internal porting changes or changes in the
crankcase pressure (vacuum).

Francis Muir

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Mar 29, 1993, 4:28:16 PM3/29/93

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I took this question to Gene Riley, the Honda Guru at Voyager
Marine, Alviso, CA. He said that the important differences were
in the carburretor and camshaft. He thought it would be more
costly to upgrade a 9.9 to a 15 than to buy a 15 outright. That
is, the price differential is about $250 and the parts swap might
be $300 + labor. He thought that a 2-stroke would take about $50
to upgrade, and that is in line with other persons sentiments. For
those interested in these things, Volvo used to make, for the Euro
market, "Fisherman" versions of their marine diesels which were
quite less powered. They cost more! These lower powered versions
are reputed to have a much, much longer life -- 25 years without
overhaul I have heard -- and are prized beasts. It may be that the
Honda 9.9 is similarly longer living. I'm probably going to get
one myself, since my wife wants the electric start and there are
possibilities for complete remote control, Start, Throttle, Shift
and Steering. Gene riley says he does a fair number of conversions
from inboards to 9.9 or 15 Honda outboards, since he can do a
complete remote outboard installation for $2700 -- much, much less
than a diesel inboard or even a major diesel overhaul.

Cap'n fido
FELIX the CAT
Port of Redwood City
California

Fabbian G. Dufoe, III

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Mar 29, 1993, 12:13:13 PM3/29/93

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In article <1op6ap$b...@gaia.ucs.orst.edu> youn...@ucs.orst.edu (Dean Youngquist) writes:
>I was looking at Honda outboards yesterday and noticed that the 9.9 HP model
>seems identical to the 15 HP model except that the 9.9 has an extra bolt in
>the throttle linkage which prevents it from opening completely. The gear
>reduction ratio is the same on both motors, also stroke, bore, and propeller.
>
>Could I just remove this bolt and have a 15 HP for the price of a 9.9 ?

When I bought my Honda 7.5 some years back I had a conversation with a
technical representative from Honda who advised me the 7.5 was identical to
the 10 except for the camshaft. By changing the valve timing they cranked
more horsepower out of the engine. I doubt you can boost the horsepower of
your 9.9 by removing the throttle stop bolt.

--Fabbian G. Dufoe, III
350 Ling-A-Mor Terrace South | GEnie: F.DUFOE3
St. Petersburg, Florida 33705 | internet: fgd3%ni...@palan.palantir.com
813-823-2350 | uucp: ...palan!deep6!nifty!fgd3

benjami...@gmail.com

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Aug 5, 2014, 5:21:26 PM8/5/14

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Yes they are however the carburetor on the 9.9 has a plate on the back of a carburetor before the intake manifold that restricts airflow making it a 9.9 instead of a 15. Removal of the plate makes it a 15 hp.