SHO-time part II


My Yamaha SHO has been on the boat a couple of months now, and I’ve had the chance to put a few hours on the motor.  Being within the official break in period, I’ve managed to get it to WOT a handful of times for really short periods.

So far, I can say that I’m still happy with my decision. At times I’ve missed the deep growl that I used to get with the old engine, but I think I can live with that…

The real positive so far is hole shot. It’s phenomenal! I’ll say it again, hole shot is phenomenal! Everyone who has been on my boat since the repower has commented along these lines.  I can honestly say that I had never experienced acceleration like this previously in my boat, and most people that you try to explain it to, don’t fully understand it until they go for a ride.  Actually, if I think about it, the acceleration is almost as good as the hole shot that I was getting in Brad Dolman’s tinnie during the Aus Open this year.  That’s a pretty big call for a boat that probably weighs close to 1400kg.

Performance hasn’t appeared to be compromised either.  I’m running the jack plate a little higher than previous, and I’m achieving a better top end speed with the 4 stroke.  The next step will be to test a slightly bigger prop than the current 25 inch 3 blade V MAX SHO Series Prop.  Given that I’m currently hitting the rev limit at WOT now, I’m thinking that the 26 inch version of this propeller should do the trick.

What will be interesting is whether I end up having to compromise on the acceleration out of the hole and in the mid range by going to the taller prop – I’ll keep you informed about that once I’ve done the testing.

One other thing I plan to do is have a water pressure gauge installed when I put the boat in for the next service.  I find myself a little nervous running blind without one.

One concern I do have is how far the motor appears to sit in the water during acceleration and deceleration.  The cowl is a bit longer than the old motor, and my boat is stern heavy. I had some initial concerns that perhaps the motor is set too low.  As a precaution, after each trip, I’ve been removing the cowl, and there doesn’t appear to be any water intake or spray visible internally.

At this point in time, I can’t really make too many informed comments about fuel economy.  I’ve been driving way too erratically during this break in period to have any real sense of how it’s performing.

I know fuel consumption was one of my major concerns about making the jump to a 250HP engine.  The previous 225HP DI engine was miserly on fuel.  In fact a standard tournament day on the water on Sydney Harbour would cost me the equivalent of about 40 litres of fuel – from what I can gather, that’s pretty damn good for a big boat being pushed along by a 225HP motor at full throttle.  Unfortunately I didn’t have an accurate fuel gauge to get any real numbers – Having said that, my perception of the amount of fuel used is averaged out over about 2.5 years and a lot of trips on the harbour…


Anyway, the new motor has me on the water, which is the main thing, and Benny is smashing me at the moment… Stay tuned for more feedback in coming weeks.

One response to “SHO-time part II

  1. Pingback: SHO-time |·

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