I have a boat with no propellers I bought it like that -ARNESON 1600 drives. I need to find the gear ratio then I can get the propellers. I tried RIK but I need more information because the boat is a $$ paperweight without propellers.

pull the drop box apart and count the gear teeth , or turn the engine one full turn and see how much the propshaft is turned .

We like to turn the prop shaft 10 turns, count the input and divide.

For example 15 on the input divided by 10 on the prop shaft = 15/10 = 1.5

If I remember correctly Second Effort only made 3 gear ratios. 1:1 1.33:1 1,5:1. I think the 1.33:1 was the most popular.

Thank you, this is what makes the forums so important now this information is recorded for all time

I've told you this before.

Mark the input shaft at 12 o'clock
Mark the prop shaft at 12 o'clock
Turn the input shaft ONE time..
See where the prop shaft is.

9 O'clock is a 1.32
7:30 is a 1.5

Thank you for the response RIK
Is it true that there are no parts for the 1600 drives?
This is what a shop tells me about rebuilding the drives if any parts are needed

"If there are significant parts needed, they are not available. Seals may well even be a problem, so my guy will not assure me that he can even get the parts to properly put them back together. They are obsolete drives."

seals and bearings are not a problem. The CV joints are an issue.

But can you get cv joints from other sources for other aplications? Rik does the kit you sell include cv joints or can you get them?

Rik's kit uses u-joints. Arneson abandoned the CV joint drives many years ago.

There is no direct replacement CV joint made by anyone for the 1600 drive.