Outboard mounting

[tsmyth]

I have just bought a new outboard mounting for my Boomaroo 22' trailer sailer (I think it was produced as a Jaguar in the UK).

I would appreciate any advice on the best position for mounting. Obviously the prop has to be deep enough in the water, and clear the rudder. Are there any guidlines on the measurements involved?

Ray

 

[William_H]

Hi Ray I am assuming that it is a fixed mount ie not adjustable for depth (adjustable is vastly better). So mount as close to centre line as poss however not so close that the rudder can hit the prop on full lock.( motor and rudder in opposite directions)
The depth is the critical part. You need it deep enough to not cavitate when there is a person on the bow ie pulling an anchor.(tends to be the worst case) However too deep will drag in the water but more importantly will be a greater reach for starting (battling) with the motor. So you need to know what the fore and aft trim is like with a person on the bow, that is how close the bottom of the transonm is to the water. The general idea is that the cavitation plate should be at or below the water surface at all times.
I am assuming you have long shaft O/B if a short shaft and a fixed bracket then you may have trouble in some circumstances. If you are motoring in a big swell for instance the motor can cavitate ie not enough water around the prop one moment then be threatened with submersion the next moment. So it is all a compromise however if you can look at the trim of your boat or photos of similar boat then decide where the water line will be. Put the motor up on blocks or similar while attached to the bracket check that you can reach the starter cord throttle etc and mark the holes when you reckon you have the right depth. I think from memory the boomaroo does not change pitch much with weight so it should be easier than my Castle (you won't talk to me now)which can vary be 10 cms at the transom depending on placement of crew. Have you looked at Trailer Sailer place for a boomerang web site? you might get more ideas. regards will

 

[dickh]

Hi tsmyth,
If you go to the UK Jaguar site and ask the question you will get lots of advice -
see http://myweb.tiscali.co.uk/westgatefamily/default.htm also the link to a boomeroo -
http://myweb.tiscali.co.uk/westgatefamily/linksframeset2.htm
Hope you get all the info you need(I have Jaguar 27)

 

[tsmyth]

Thanks, William and DickH.

Sorry, I should have made the point - it is an adjustable mounting.

One problem is that, with my limited strength, there is no way that I can open the mounting against the springs to measure its length when open. So, I cannot work out how low the mounting board will be at its lowest point (of 4 possible) to allow me to estimate the position of the prop when it is down.

Ray

 

[FlyingDutchman]

Can't you remove the springs?

 

[aitchw]

Bolt it to something else, bench, door, fence anything strong enough, and mount your o/b to it. You will then be able to move easily between settings and make whatever measurements you need.