Originally Posted by Bad to the bone

do you have a link to your resort

Originally Posted by iliveonanisland

I want to build a diesel powered boat to haul people to my island hotel. It’s an hour and 45 min trip each way. 365 days a year. The boat we have now we bought used and it holds 40 passengers. And when we bought it had a pair of 200hp Yamaha outboards. The boat ran 29 mph with the engines turning 5400 rpm. Looking at a pair of yanmar 250hp 4cyl turbo diesels and arneson six drives. Waiting for the yanmar dealer to tell me what ratio transmission to spec with the engines and what diameter and pitch prop for the asd #6s. Called twin disc which I guess now owns arneson. The application dept is who I have to speak to and they cant be called only emailed. It’s been a day and a half since I asked them the tq handling capacity of the sixes. So no idea when I will receive a reply From then. So reaching out to oso bros.
. The 250 yanmars make 342ft lbs of torque. The boat is 42ft and holds 40 passengers and baggage in the bow compartment should I shoot for the same prop speed that the Yamaha 200s ran. They ran a small 15 pitch prop. That boat currently has a pair of Yamaha 300s and runs a 19pitch prop.
i think running outboards is retarded. They are shot at 2200-2400 rpms and not worth much to sell the puke lower units often as they are so heavily loaded. Plus the fuel saving is huge. The yanmar as supposed to consume 4.9 gph per engine at cruise which I assume is 3200 rpm which is 85% of max rpm of 3800. So apprx 40 gallons round trip. Current boat burns 130 per round trip when full up. Thank in advance for any info, RM

Originally Posted by Bad to the bone

do you have a link to your resort

Originally Posted by ICDEDPPL

must be a hopping place, no posts on insta and the facebook page is gone.

Originally Posted by tommymonza

Stay with the Yamaha's, trust me you will regret every moment you thought of anything else.

If your only getting a couple thousand hours out of them you got them over propped or getting them hot. My dads boat had 5000 hours on his Yamaha 175when sold it and it still had great compression in every cylinder.

I fought with the little 6 cylinder 245 horse Volvo s back in the day with my commercial parasail boat, than Yanmar came out with the 6cylinder 4 liter 300horse that was going to be the return of the Messiah .

Nope at 1200 hours it was only producing 75%power because of wear and Yanmar said it was overpropped turning 3800rpm when their recommendation was 3600-4000 rpms. So after a year I bought another new yannar that was now rated at 315horse at 3800-4200rpm, that was good for 2100 hours.

Those little 4cylinders will never survive the varying torque loads of a surface drive , and that is if you ever get them propped correctly. You ever wonder why you see so many big high speed yachts ditching their Arnesons? Its because the sensitivity of weight and trim causes the load on the props to wildly vary causing the big diesel's to be lugged without the operator even being aware of the condition.

Even if you used direct shaft drives with those little yanmars you might get 2500 hours but you will lose so much speed and efficiency compared to the Yamahas.

Originally Posted by iliveonanisland

noboody down here is getting much over 2k hours on the 300 Yamahas. That’s what it takes. Not over propped the boat runs 4400 rpms 30mph. One dude has trip 200s he has 3k hours on them. Can run trips on my boat. Not wide enough. Looming at lugger and cummins diesels over the yanmars. The dude that owns simplicity drive has customers with 6-7k hours on the new yanmar 4LV 250s with no issues. But it’s a lot more weight and a little bigger size wise with the cummins waiting to get the lugger specs