9.9hp mercury

[johnyp]

Hi everyone just got another boat after a few years its a 3 year old zodiac 310
with a 3 year old 9.9hp mercury four stroke std shaft I have been told the only difference between a 9.9 and a 15 is the carb or carb jets can anyone confirm this.
And if it is correct what it entails to convert to a 15
Regards
johnyp

[Fenlander]

Assuming your motor is a 4-stroke not a hookey 2-stroke...

In your manual check your engine cc. I think around the age of yours the 8 & 9.9 were basically the same motor with a capacity of just over 200cc. The 15 & 20 were then similar motors based on the 323cc (or thereabouts) powerhead.

[johnyp]

thanks I will dig out he manual and have a look
regards
johnyp

[johnyp]

hi yes it is a 209cc so looks like its not doable to upgrade to 15 hp
thanks
johnyp

[Fenlander]

As long as you don't carry a heavy load a 9.9 should be fine on a 310.

[johnyp]

that's the problem I am approx. 14 stone but my mate is approx. 18 stone lol
and then all the gear I think I will have to leave him at home ah

[Fenlander]

All SIB and OB combos perform slightly differently but my experience with 10hp on 3.1/3.4m SIBs has been they will plane fine with two adults total 28 stone (plus fuel and kit)... or one adult and two children total 28-30 stone. Once we tried two adults and one child getting up to 35 stone it became harder to plane.

[johnyp]

I know I think maybe next year I will upgrade to a bigger boat and engine not sure to get air floor or ally