It all started when I won a propeller in the twilight series. I was pretty happy because it was a beaut Gori two-blade folding prop and I'd recently been thinking that the three-blade self-feathering prop I had on was a bit big. I was about to change it anyway.
To cut a long story short, it was a case of the classic up-sell. The guys at Yanmar who import the Gori props said that they'd match the trophy to my tired Volvo MDII. However, they said that if I ever wanted to upgrade the motor, I'd have to get another prop because the Volvos throw left and everything else throws right.
Well, we got talking and as it turned out the old motor was showing signs of needing either a full rebuild or a replacement. The engine was smokey and I didn't have much confidence in it. In fact, ever since I bought the boat from columnist Jesse Martin I'd had trouble with it.
Yanmar happened to be running out the old 3GM30 engines to make way for the new 3YM30s, so there were some runout deals to be had. But still I ummed and ahhed.
The final straw came when I took Lionheart out for a sail with Antony, Trade-A-Boat's sub-editor, and we lost all oil pressure on the way in.
I'd had enough - I immediately rang the Yanmar boys on impulse and ordered a runout 3GM30.
MONEY MATTERS
Sometimes you have to bite the bullet and pay for reliability. Sure, I could have rebuilt the old motor - but it had had water in it, and throwing good money after bad isn't a habit of mine.
Neither is paying retail, so imagine my chagrin when the state manager from Yanmar rang me and said that the runout 3GM30s had done just that - run out!
I was now determined to get my new donk, so we struck up a new deal (which was still good) and I was in line for one of the first 3YM30s.
I got Gary Miller from Miller Marine in Melbourne to take a look at what would be required to swap the motors and he gave me a loose quote.
As I soon discovered, it wouldn't be cheap: we'd have to change the engine mounts completely and cut and shut the floor bearers a bit - then possibly re-route the exhaust and the fuel lines.
If you're planning to change your engine, it's a good idea to get the quotes before you order the new one - I got a bit of a shock when it finally came time to pay!
Grinding and rebuilding engine mounts is not something you'd try by yourself, and it did cost me about two grand more than I'd estimated (and it made a bloody great mess in the boat).
I found that my Yanmar has the exhaust and fuel inlet manifolds on the reverse sides to the Volvo, which didn't cause too much trouble - but just enough to be a pain.
SWITCHING OVER
Next it was time to fit the switch panel, which has a tacho, oil, ignition and temperature lights as well as an engine-hours readout in the tacho.
The old Volvo panel had a temp gauge, which I thought was a good inclusion - I might add an aftermarket one in the future.
I had initially thought that I could offset some of the costs of the new motor by selling the old one, but that didn't really come to fruition. When we took out the old one, we found it to be in worse condition than we'd initially thought. So rather than fix it up and try to sell it as a going concern, I got rid of it cheaply to another mechanic who could fix it at his leisure.
I really wanted the new motor to have no weak links, so I ordered a new Morse controller and new cables.
A slight problem when we were lifting the boat out to put the new Yanmar in led to a new prop shaft as well. The consequence of all this was that the whole driveline from flywheel to prop is new.
RELIABILITY: PRICELESS
Sure, it has cost me a lot of money - but I want to take Lionheart out to sea from time to time so I'm happy to spend the money knowing that every time I turn the key, it's going to work.
An added bonus is that the engine is freshwater cooled, which should add to its longevity as well as giving me a heat exchanger from which I can run hot water in the future.
Being a modern three-cylinder engine, the Yanmar is a revvy little number. It's rated to 29hp, which is up in power from the 23hp of the old Volvo. Consequently it'll take Lionheart up to about 7.6kt at Wide Open Throttle, which is 3600rpm.
Certainly that's overkill - I generally run it between 2000 and 2500rpm, which gives me a nice cruise of 5–6kt.
The engine is smooth in its running and quieter than the Volvo. And yes, I'm very, very happy with it. Now all I have to do is make the engine box fit properly and it's all over...
YANMAR 3YM30
Power: 29hp @ 3600rpm
Displacement: 1.115lt
Bore x stroke: 76 x 82mm
Cylinders: 3
Cooling: Freshwater with heat exchanger
Dry weight: 133kg
Height: 545mm
Length: 715mm
Width: 463mm
Published : Friday, 1 October 2004
Issue : October 2004
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