RL24, RL28, and RL34 Trailable Yachts
from Rob Legg Yachts

RL Yacht Owner's Discussion Forum

Return to the Forum List

Volvo-Penta Diesel Vs 4 stroke outboard
Hi Guys.
Well I am in a bit of a pickle over what to do with my engine, so I thought I would ask you guys.

My RL28 "Sandpiper" engine, a Volvo Penta 2001 model diesel, recently locked up due to a lack of use on my part. We removed the motor and had planned to do a complete overhaul. The original problem was a simple fix. A valve stayed open after the engine was shut down after a day of sailing causing corrosion on the rings after a couple of months of no use.

Anyway, the cost of a minor rebuild (new rings, gaskets and bearings) is still going to cost around $4,000.

I always said that I would NEVER consider putting an outboard motor on the boat should the diesel ever fail, but with the advancement of 4 stroke outboards these days, I am now starting to reconsider my options. A brand new Mercury 9.9hp Bigfoot 4 stroke outboard, with forward controls, electric start and power trim is only $4,700.

The Pros of the Diesel is its good fuel economy, diesel is safer to carry on board and ease of use. The down side is a permanent saildrive leg dragging in the water, and also the age of the saildrive. It works fine now, but what about down the track??
The Pros of the outboard is no drag in the water while sailing and a brand new motor (with drive leg). The cons of the outboard is having to carry petrol on board, not as good economy as the diesel and noise.

What is the opinion of other RL28 owners on this group?

I would love to hear your comments and suggestions.

Garry Beattie
Garry Beattie 14-Sep-2012    Edit    Delete 
Re: Volvo-Penta Diesel Vs 4 stroke outboard
G'day Garry, I have a 10hp high thrust yamaha which pushes the boat along very well, although I suspect it is not as good in reverse as an inboard would be. The only other thing I would add is I have often thought a heat exchanger fitted to an inboard would save a lot of expense and trouble if you wish to install running hot water compared to a gas instalation.
Interested to hear what others think on this?
Jason 24-Sep-2012    Edit    Delete 
Re: Volvo-Penta Diesel Vs 4 stroke outboard
Hi Jason.

Thanks for the comments, and thanks also to the people who emailed me with their idea's and suggestions.

I have decided that I will repair the Volvo Penta diesel.

I weighed up a lot of variables and it was very tempting to buy a brand new Mercury 9.9hp, 4 stroke Big Foot motor, with hydrolic tilt, electric start and forward controls. The cost would have been $4,700 fitted, but I would have had to modify the boat to accommodate it. I considered the bomb door idea but felt uncomfortable modifying the original boat hull. I looked at mounting the outboard motor bracket to the rudder box so that the motor steered with the rudder, but I was concerned about the weight (38kg) on the rudder brackets.

I also had the weigh up the idea of carrying petrol on board, rather than Diesel. For safety reasons diesel is a much better choice. And at a little over 1 litre per hour (at 6 knots) fuel burn with the diesel, it is very economical to run.

The other consideration was the charging power. Even though I have a 130w solar panel fitted, on extended cruises in our boat we sometimes need to top up the house batteries by running the engine. The outboard would only charge at 6amps max, whereas the diesel motor alternator charges at 55 amps.

The final consideration was originality. Rob Legg would have put a lot of consideration into inboard Vs Outboard when designing the RL28, and he opted to use the inboard. Rob would have more boat design knowledge in his little finger than I would ever have, so I felt uncomfortable changing the design.

So for about the same money as a new outboard, I will totally recondition the Volvo Penta inboard. That way I will keep the boat original, will have plenty of charging power from the motor and will carry a safer fuel source on board (diesel rather than petrol.)

I just hope I don't live to regret my decision!!!!

Garry Beattie 8-Oct-2012    Edit    Delete 

Return to the Forum List       Add a message to this discussion