My experience has been a little different than yours, RF. I had a 200 FICHT that would burn 45 lph at a cruise of 24 knots and weighed 538 lbs. when the oil tank, and extra 4 litres of oil were included. My new 250 Yammie weighs 558 lbs. and burns 35 lph at the same cruise.There is a huge difference between older designed larger two strokes and more modern 2 stroke designs like Opti’s. My Opti never smokes at all. In fact it runs cleaner than many 4 strokes who’s valve seals are getting a little tired especially, when starting up. We just had the gear box off to rebuild the water pump and the exhaust was very clean and I suspect as clean or cleaner than most 4 strokes. We do burn very expensive DFI oil in it that has its own added cleaners.
As for fuel economy I think the Opti’s do as well as modern 4 strokes because of their Direct Fuel Injection. That technology is now being used on the latest most fuel efficient cars to squeeze every last kilometer out of a drop of gas.
So what about differences. Well you can barely tell my friends big Yami is running when it is at Idle but no problem knowing when an Opti is running and no mistaking that Opti roar when you open it up. They are also a lot less complicated to rebuild than a 4 stroke because there is no complex valve train and they are considerably lighter than an equal hp 4 stroke. Not that you will notice much of a difference in cost if Merc does the rebuilding.
I am often amazed at the difference in fuel economy when compared with older designed Merc two strokes. One of my fishing partners has an older 17 footer with an old school smoky 2 stroke 100 hp main and a 15 hp 2 stroke Merc kicker. Both these motors burn gas like flushing a toilet when you throttle up.
By comparison my 22 foot much heavier hand laid glass boat with a 225 Opti and a 9.9 Yami 4 stroke kicker, burn about the same amount of gas for a days fishing as does the old 17 footer with its old school Mercs. Sure the Yami blows the old 15 hp two stroke away fuel efficiency wise but the 225 Opti seems to burn very little more gas than the old 100 hp Merc despite have 2 more cylinders, 125 more horse power and pushing a much bigger heavier boat.
My experience has been a little different than yours, RF. I had a 200 FICHT that would burn 45 lph at a cruise of 24 knots and weighed 538 lbs. when the oil tank, and extra 4 litres of oil were included. My new 250 Yammie weighs 558 lbs. and burns 35 lph at the same cruise.
So 10 less litres per hour (about $14.00) plus no DFI (at 100:1 x 45 lph = .45 litres of DFI oil x 14.00/litre = $6.30), I am about $20 per hour cheaper for the same results. The fuel monitor proved it to me and I am completely sold on 4 strokes.
My experience has been a little different than yours, RF. I had a 200 FICHT that would burn 45 lph at a cruise of 24 knots and weighed 538 lbs. when the oil tank, and extra 4 litres of oil were included. My new 250 Yammie weighs 558 lbs. and burns 35 lph at the same cruise.
So 10 less litres per hour (about $14.00) plus no DFI (at 100:1 x 45 lph = .45 litres of DFI oil x 14.00/litre = $6.30), I am about $20 per hour cheaper for the same results. The fuel monitor proved it to me and I am completely sold on 4 strokes.
Good laugh RF, thanks for that. No doubt the Opti's are much better than the first generation DFI's. Each of the newer models (2's and 4's) are light years ahead of what they were even as little as 6 or 7 years ago.Just checked the specs and a 225 Opti weights in at 497lbs although some versions may be a few lbs more. It gets about 45% better fuel economy than older designed 2 strokes and is happy with 87 octane. The local Whale boats can get many thousands of hours out of them and they push them very hard all the time. For some reason they prefer the Opti DFI 2 strokes and it sure is not because they are cheaper to buy. Firing every two piston strokes instead of 4 gives them a great hole shot.
Don’t know much about the FICHT but my impression is that they are no Opti.
I will concede the new big Yami’s 4’s get a bit better mileage but the Opti’s are close and a big improvement over older two strokes.
Letting it go now; I am starting to sound like I am getting the ruler out to measure my dick.
I don't troll on the main so I never have to smell 2 stroke fumes anyways, only the guys following me out in the morning do
Curiosity made me check some Yamaha specs
the F70 4 stroke weighs in at 257lbs
the 75A 2 stroke weighs in at 248 lbs
Virtually the same weight