Need LU gear ratio information

[pecheux]

Hi y'awl, I need the following information in order to decide on a prop pitch. Would anyone know the LU gear ratio for the two following OB's ???

1981 Johnson 9.9 hp
1997 Force 15 hp

Thank you,

 

[Silvertip]

Re: Need LU gear ratio information

While I don't have the numbers off the top of my head, it is easy enough to determine. Remove the engine cover and turn the engine manually while you count the number of turns of the flywheel to make the prop turn once. While not precise, it will get close enough for the prop calcualtor. 2.5:1 means the engine turns two and one half revolutions to make the prop turn once.

 

[pecheux]

Re: Need LU gear ratio information

While I don't have the numbers off the top of my head, it is easy enough to determine. Remove the engine cover and turn the engine manually while you count the number of turns of the flywheel to make the prop turn once. While not precise, it will get close enough for the prop calcualtor. 2.5:1 means the engine turns two and one half revolutions to make the prop turn once.

Thank you for your suggestion. Nevertheless I sure wish someone would know the exact numbers because the pull crank housing on the Force 15 hp covers the flywheel.

Tx