9.9 horsepower?

[stauter99]

I have been thinking, why do "they make 9.9s or 9.8s etc. Just out of curiosity does anyone know?

 

[JB]

Re: 9.9 horsepower?

Hi, Stauter.<br /><br />Many lakes have a "under 10HP" limit on engine size.

 

[wupdike]

Re: 9.9 horsepower?

My understanding is that 9.9 signifies a powerhead, and lower unit specifically configured for a sailboat. The shaft is longer, my Evinrude has a 4-blade prop, and the 15HP design has been altered to emphasize the lower RPM and higher torque needed on displacement hulls.

 

[Solittle]

Re: 9.9 horsepower?

Warren - The 9.9 and 15 are very popular motors for sailboat auxiliaries with the long shaft. They are very much multi purpose motors. They are also popular for power boats both as a second "get home" motor, trolling motor and used as the only motor on small boats. Depends on what you need a motor to do. No special design considerations that I know of for sailboats other than what you mentioned that many will go for a power prop.

 

[MFG197]

Re: 9.9 horsepower?

firstly many manufacturers use the same powerhead for 8, 9.9, 15 hp motors and it has nothing to do with sailboating. they do make sail boat motors a la Johnson Sail Power 9.9 becuause of the extra long shaft needed for sailboats and they have an alternator.<br /><br />Many lakes have a 10 hp limit. Meaning that you could use a 10hp motor...like an old chrysler that was 10 hp. The 9.9, 9.8 etc. is because an outboard under 10 hp does not need a title (at least in Ohio). The motor probably makes 10 hp becuase hp rating can be stated by the mfg. within a certain % of the actual hp. A merc 150 can make 155 hp and a Force 120 can make 115. Just like a boat under 14' does not need a title (in OH) so there are a lot of 13'11" fishing boats. <br /><br />correct me if I'm wrong.