I will say quite happily that I really like the Suzuki 140 4-stroke unit - have said this before and will say it again.
When trolling around the local coast slowly it's great, you can hear everything what's going on around *but* the engine.
Granted, it doesn't have the same 'get up and go' as the 2 strokes - even my last boat with a 2stroke 70hp was instant power up. But..... when you throttle up, whether there is 1 adult or 8 adults plus supplies (food), it seems to wind up at about the same pace - it doesn't reach max revs though, and 8 adults reduces top speed to around 34knots at WOT whilst making around 5500revs.
My engine at WOT with 1 person on board reaches about 5900 revs (the stated max in the manual is 6200revs which I believe Martin Stacey can reach on his Ribcraft) running 21" stainless prop from steel developments. With 2 people on board, it'll make 6000revs - don't ask me why - I think it's weight distribution.... my fuel tank and me are right up front on the boat, where as with a 2nd person that person is towards the back which gets the bow up a bit higher I think.
The other weekend we went around to Tenby and back - 60 miles or thereabouts in total, with a fair amount of low speed, and high speed stuff. On the way out there we were cruising at around 4500revs for 50mins, which takes me to around 25 to 28 knots. On the way back, given that we didn't have long to make the lock, we were pushing 5200revs and making 34knots in some fun chop until the fog where we only made 13 at a lot lower revs.
Once clearing the fog, it was WOT for the remaining 10 miles to make the lock with less than a minute to spare.
So, fuel used - about 45 litres, good, bad, I don't know, and don't really mind - that's exactly half my fuel load on board which means given similar conditions the rib is good for cruising past 100miles distance.
The gps shows 4hrs and 42mins of moving time, which is probably about right, but in that time, the engine was idling during lunch, and also in the lock when we were back in milford - it probably ran between 5hrs 30 to 6hrs that day (I usually idle the engine for a while after long term higher revs to cool the whole thing down).
The servicing is not cheap - my first service was £98 inc vat for oil change in the main engine, gearbox, and oil filter change with greasing etc.
The 2nd 100hr service which I have just had included the aux engine, plus impellor and a few extra bits for what I believe is a lot more (the invoice is in the post to me apparently).
Now, my sister calls this "really sad" to take pictures of the boat engine, but she hasn't come up with a comment about taking videos yet......
Here's 2 sections of video in one from when we went out to Skomer Island, both taken on the way back up the river.
The first bit is doing between 3500 and 4000revs at just over 20knots, the 2nd bit shows increase in revs to 5000revs and maintaining 32knots for the remainder back up to Milford Marina.
This link should 'stream' for broadband owners - dialup users will have to download first.
The whole thing is on the link below and is nearly 7meg:-
Some either useful or non useful figures for you there, I don't have a fuel meter so dont know my exact fuel use when at WOT, I only go by what fuel I put back into the tank at the end of the days trip.
What I will say though is that I prefer the sound of the optimax engines - there's a cracking rib down here with 225 opti on the back, and on a calm evening, the growl from that as he throttles up sounds really really good - I think the V6 makes a nice difference there