Rudder question for propeller jetski... best guess please ?

What size area for jetski rudder?

Can I use a balanced rudder? (easier steering)

What shape and size would be best to start with?

550lb jetski 80plus mph


thank you for your time

 

No you cant put a rudder directly in front of a surface prop. Nothing should disturb the clean water flow to such a drive. Not even a skin fitting for water intake is advised. It will have to go behind and a fair way behind. you may have to make a bracket. Theres plenty of pics on the internet of various drives that have bracketed rudders.

 

Rear mounted rudder while not impossible is something I am hoping to avoid. It would be easier for me to mount 2 small rudders on a bearing supported shafts on either side of the prop with back of rudders being about 1in behind the back of propeller.

I was thinking something like 2 of these
http://www.boatzincs.com/MER34127A.html
mounted on rear corners of ride plate with connection bar

First passes will ofcourse be slow to feel out handling and work from there... do you feel 2 rudder tabs of this size would be adequate to start with on 9ft long ski?

 

How far away from the transom is the propeller? This sounds extremely dangerous. Are you going to cover the prop somehow, if you slid back off this this thing it will do more that cut your nuts off.

I would think a boat so small would not be able to do such speed in a controlled manner.

The trim tabs are too small and you need to weld a shaft to them.

I think I would be making a bracket /cover that gets the rudder in the right place and gives some protection of that prop.

 

edited

 

my concerns....

edited