Mariner 8 vs 9.9 HP four stroke outboard

[danilo]

I have Mercury Mariner 8HP four stroke outboard.
Does anyone know the difference (apart from HP) between 8HP and 9.9HP Mercury Mariner four stroke models from 2005 & 2006 (2007)?
Both engines look the same and the data in the brochures is identical including the weight.
Have Mercury restricted 8HP in some way or 9.9HP has different carb&jets too? Would appreciate if anyone has any info on this.
Please see the photo of my 8HP below if this helps.

[Locozodiac]

Originally Posted by danilo

I have Mercury Mariner 8HP four stroke outboard.
Does anyone know the difference (apart from HP) between 8HP and 9.9HP Mercury Mariner four stroke models from 2005 & 2006 (2007)?
Both engines look the same and the data in the brochures is identical including the weight.
Have Mercury restricted 8HP in some way or 9.9HP has different carb&jets too? Would appreciate if anyone has any info on this.
Please see the photo of my 8HP below if this helps.

8 & 9.8 models are the same engine, both 209 CC, 8 carb restricted, that I know there isn't any 9.9 model in four strokes only in two strokes, next four strokes models/range are 15 & 20, both 351 CC, 15 being carb restricted. 8 & 9.8 weights the same 37 kilos, All Tohatsu made in Japan.

Happy Boating

[danilo]

Originally Posted by Locozodiac

that I know there isn't any 9.9 model in four strokes only in two strokes

Mercury/Mariner have been making 9.9 four strokes in 2004,2005,2006,2007 and 2008 see attached.Short shaft 8 and 9.9HP weights 38kg.

[Locozodiac]

Originally Posted by danilo

Mercury/Mariner have been making 9.9 four strokes in 2004,2005,2006,2007 and 2008 see attached.

Probably a special number series for Mariner/Mercury brand, Tohatsu has not a 9.9, anyway same CC for 8 & 9.9. Strange cause 9.9 and 15 used to be the same, only carb rstricted.

[m chappelow]

i have a tohatsu 8 hp 4 stroke 2 years old and looking in the spec in the manual it is pared with a 9.8 the only difference that i can see is the main jet size and a different prop , everyone tells me that my tohatsu is just the same as a mercury /yamaha 8 hp 4 stroke.

[ian parkes]

Could it be as i was told here that one manufacturer measures the power at the crank while the other measures at the prop ?? just an idea

[danilo]

Originally Posted by m chappelow

i have a tohatsu 8 hp 4 stroke 2 years old and looking in the spec in the manual it is pared with a 9.8 the only difference that i can see is the main jet size and a different prop , everyone tells me that my tohatsu is just the same as a mercury /yamaha 8 hp 4 stroke.

Are you able to post some pics of your outboard here?

[reinier]

Originally Posted by ian parkes

Could it be as i was told here that one manufacturer measures the power at the crank while the other measures at the prop ?? just an idea

No, since around '80-'85 all manufactorers switched measurement from crank to prop, 100hp equals roughly 85hp on the prop, so a 15% loss. Nowadays every hp measurement is @ the prop.

[mdziam_78]

Hi Everyone,
im looking for information about upgradeing the 8HP to 9.9.
In parts catalogue the differences are in Carburetor, main jet, main nozzle and plug serial numbers.
The ingnition components are the same.
Can someone tell me is there a chance to upgrade the motor without changeing the carburetor? - getting new main jet, main nozzle and plug?!
thanks
MDD

[Turbodiesel]

Looks like the only difference is the carb.