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Transom mounted outboard and the Whitsundays
Hi to all,
My problem is i've found a nice rl24 but a friend recommends moving the outboard back in to the cockpit due to cavitation. Is this true? Also the hull has been glassed up,so not sure of how big a job this could turn out to be as I can't seem to find any pics of the original setup, and there are not to many Rl's up here.
Thanks in advance Mat
Mat C 27-Jan-2012    Edit    Delete 
Re: Transom mounted outboard and the Whitsundays

I have a 6hp on lifting bracketing mounted on the transom.

To answer your question simply: I am guess that most people are going to say move it because yes, there are cavitation issues when transom mounting. Once the chop gets up the bow starts bouncing, the motor will start to cavitate.

The issue gets worse the slower you are going (ie: manoeurving or raising/lowering the main), once the motor starts driving it helps push the stern down alittle.

I was getting tempted to move the motor back in however I was not keen on losing the cockpit space and I prefer the maneuvrability (I can turn the motor 90 degs and spin the boat inside its own length)
Andrew 27-Jan-2012    Edit    Delete 
Re: Transom mounted outboard and the Whitsundays
I am surprised that your are having propeller cavitation problems, are you sure its not just the engine exhaust coming out of the water when going over waves or having someone for'd when lowering the mainsail or anchoring?

Even worse it may be that the outboard bracket has been fitted to the hull too high up for a standard shaft length outboard and the propeller is also sucking air down (this is not cavitation).

If you are not into racing and your Rl24 is not a mark 1, by all means put the engine back in the well . I found that the boat handles much better under power and the engine prop. and exhaust will also be deeper in the water. The engine will also be protected from any contact with other boats and jetties. It will be easier to start and if need be filled with petrol when in the well.

Cavitation on low powered outboards can be a problem and the outboard manufacturers are aware of this. On low powered outboards they usually offer you a choice of two propellers, one for planing boats ( tinnies) and the other, heavier displacement boats (Rl24).

If you indeed have true cavitation problems I suggest you check out the propeller blade pitch or numbers (usualy cast into the hub) and also that the blades are not damaged or bent. Then check out the manufacturers website to make sure you have a displacement propeller fitted to your Rl24.

Hope all this helps
Alastair 28-Jan-2012    Edit    Delete 
Re: Transom mounted outboard and the Whitsundays
I should have explained a little clearer. I have not purchased the Rl24 mkII as of yet and am just seeking more information regarding transom mounted outboards. I have read with interest the difference of opinions regarding this matter, it's just that I live in an area where it can be a little unpredictable at times. My friends beliefs are that if I were "caught out" around the islands with 4 knts of tide and anything from 15 to 25 knts of breeze he would definately want the outboard in the well. Just looking for different views regarding this matter as the boat I am currently interested in is a transom mounted outboard with the well all glassed up.
Mat C 28-Jan-2012    Edit    Delete 
Re: Transom mounted outboard and the Whitsundays
My yacht had an excellent Honda on a stern bracket when I bought it.

The transom mounting was done in the belief that it made the yacht faster when racing.

I found handling the yacht when approaching jetties and other close work a nightmare with the helmsman needing to move back over the stern to operate the outboard. It might be fine if your a gymnast but for most normal people its a nuisance and potentially unsafe.

My yacht is a Mark 4 with the well mounting bracket 50mm further forward than most other RLs. It was easy to cut a long slot in the bottom of the well and put a new short shaft Mariner 5hp two stroke with high thrust propeller in the well.

After 8 years, I never regretted the change to the outboard in the well, the outboard is easy to control being next to the helmsman and it tilts inside the stern when sailing.

If you buy the RL24, its worth adding the cost of changing the outboard position into your budget, even if it means buying a new (and reliable) outboard.

Other comments about high thrust propellers are very relevant, especially when buying a new outboard. Dealers will often sell outboards with the wrong propellers because they don't understand or don't care.

Search this RL site for outboards and you should find some good information.

This site http://www.trailersailerplace.com.au/phpBB3/ also has good discussions on various issues with outboards like 2 stroke verses 4 stroke.
Greg 28-Jan-2012    Edit    Delete 
Re: Transom mounted outboard and the Whitsundays
If you don't have a stern pulpit or lifelines and you are planning to sail in the whitsundays, move the engine to the well. Regardless of cavitation, it's really asking to go for a swim having a stern mounted motor. The job really isn't that big but I'd get a pro to do it unless you're very handy. Any sacrificed performance due to drag is more than compensated for by having that weight shifted a good metre forward.
James Shannon 30-Jan-2012    Edit    Delete 
Re: Transom mounted outboard and the Whitsundays
Having made the other change (outboard from well to transom) and not regretted it one little bit and having done a bit of Whitsunday cruising in Hartley 16's and 18's, my answer would be to not make any changes until you have spent a bit of time with the boat in its existing configuration.
Mike 31-Jan-2012    Edit    Delete 
Re: Transom mounted outboard and the Whitsundays
I am in the process of moving the O/B back to the motor well. Not a difficult job. After I bought my RL24 I discovered that the weight of the O/B mounted on the transom had damaged the join between the transom and the aft deck, they had come apart from the rudder mount to the starboard side of the stern. Required repairs to make sound. I figured if Rob had designed the yacht to have the motor in the well then that is where it should be, the transom doesn't seem strong enough.
Richard 9-Feb-2012    Edit    Delete 
Re: Transom mounted outboard and the Whitsundays
I recall my first venture in spirited winds on the Gippy Lakes. Trying to get back into Loch Sport at the end of the day, with a strongish SSW breeze, I had to give up on the iron sail due to the prop's spending far more time out of the water than in .. whereupon we spent the best part of the next hour tacking from the northern side of the pond to the ramp. I thought it good fun, if a waste of time, but Sal was less than impressed ..

I am planning a refurbish this winter and one of the main aims will be to get the motor back into the well.
John Heddles 13-Feb-2012    Edit    Delete 
Re: Transom mounted outboard and the Whitsundays
Thanks for all the input,
Unfortunately after a closer inspection the boat needs a little more love than I currently have time for. Ho hum
Back to the drawing board.
Thanks again
mat c 15-Feb-2012    Edit    Delete 

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