Finally got me a Dyne! Power options?

Mercury Marine lists the 150 proXS weight at 431.

The 115/125 two stroke is 375 which is more than my 150 like I said before.

My 150 is actually a bass boat motor and actually puts out 164 hp. There was also a 175 that same year that also weighs 370. I can hear at conversational level at speed, but my fuel comsumption is more.

However, at swivel or child speed the fuel consumption is about 2.5 gallons per hour. The boat is nice and light which really helps with fuel consumption. I don't use the boat enough to matter either way.

You mentioned that your team runs an 18 with twin Optimax V-6's. Does the boat have any ballast in the bow, and does it have porpoising issues? Are the engines mounted on wedges?

jim

 

For your use, the Verado and Optimax fuel consumption would be minimal and the differences between either would be unnoticable.

A waterskier will notice approximately a 50% reduction in fuel consumption when changing from an 80's tech 2 stroke to a DFI 2 stroke like the Optimax or E-TEC (not the HPDI Yamaha as that is missing the low RPM lean burn that we waterskiers use a lot).

Twin 115 four strokes - would be a wash compared with a single big block 3.3 litre 200 HO E-TEC I would guess. Holeshot and top end would probably be similar with either setup.

I think you want some stick and you want new engines!

I love the idea. If I did it, I would be prepared to fiddle with the thing for a while to optimise it.

Twin Optimax engines would be awesome.

I can't remember why you want Mercs but if it were me I'd do it with twin E-TEC 150's. They are refined, quiet and lovely engines. For your use, they will have the same fuel consumption as Optimax, Verado. Without careful measurement, you couldn't tell the difference in fuel consumption between those options, for your use.

I'd be prepared to put up with some extra weight from new tech engines. It might make the setup take a bit longer to get dialed in but you'll get there.

As far as grunt, the new big block 2 stroke outboards would amaze you. A 200 HO E-TEC would smash the old twin you mentioned in a drag.

But you want twin engines. And if I could, I would too.

One day, I aspire to having a tripple (750hp plus) 20ft dyne in my shed. I'd get it out only a few times per year but it would make me smile every time I walked in there.

Greg

 

Thanks ghind for an excellent post that answeres alot of my questions but of corse makes me ask more.

1st of all the reason I want Mercs is because that is what I am used to, and I have some special tools for Merc use. I have nothing against E-tech or any other major brand out there but I am a Merc guy and want to stick with what I am familiar with.

I do want new motors or close. With the use I will put on them a pair of not abused newer would be ok. No old tech here - especiallally after what I read in your post about the new stuff blowing me away from what I drove back in the 70's - performance wise and fuel economy wise.

I do love the idea of putting cutting edge technology on the back of my boat (Verados) and am willing to take the time to dial it in. Many members of this forum have advised against this as the extra weight would not be good - they are right but I am very experienced with driving ass heavy over-powered boats.

So if the fuel economy of the modern 2 strokes is close enough to the 4 strokes that is not an issue.

The only issue that remains is the noise. The Merc Opties are among the noisiest out there in their class but I am thinking that at 2500 - 3000 RPM's they would not be so bad. That 16' boat I drove in the 70's had twin 115 Johnsons and at ski speeds was quiet enouf but when wide open it made some noise.

Good stuff! Keep it coming!

Thanks - TJ

 

I don't think I'd be putting twin Verados on an 18 ft dyne. Maybe a 20ft dyne if you really, really had a thing for those engines.

If you want the quietest, most refined, best dyne you want an E-TEC powered one not a Verado one.

If anything an Opti or an E-TEC will be more economical than a 4 stroke for a waterskiing application, not the other way around.

The Optis would probably be quieter than a 70's Johnson. The 115 Johnson in the 70's was rated at the flywheel not the prop so the engine was realistically 100hp in today's numbers - or a bit less. They were a 1.6 litre engine. I'm pretty sure my 3.3 litre 225HO E-TEC would smash the performance from pulling, midrange and top end of that combination.

The V4 OMC (Johnson) engines were very light. Even though they weren't that strong, there is no way I'd consider a twin 115 4 stroke Dyne. Expensive, ass heavy and I think a waste of time. You get the look of two engines, the weight of two heavy engines, the price of two expensive engines and you don't even get the nearly the performance of one!

However you are really set on twins. You do need to keep weight down a bit - even then you are still very much pushing it. There has been some very good advice in earlier posts.

The 150 Verado is 510 pounds each dry for the lightest model! That is exactly the same as the weight of my 225HO E-TEC!!!! The 150 E-TEC is 418 pounds.

With 13 people in my boat, my 225HO will pull 4 adult slaloms out of the water comfortably. My boat probably weighs the same as 3 18ft dynes. I've pulled 13 on doubles from a deep start. Same prop pulls 63mph GPS on the RPM limiter. With 8 adults in the boat, I pulled 3 barefooters plus one who wouldn't get off his stepoff "too FAST!". I think it was 45mph, from memory and I had plenty more left.

I'd scratch the idea of twin verados on the 18ft dyne. You might be able to make one work and the 200 Verado would be as "anything" as the 1970's twin ever was.

Even twin new 2 strokes on an 18ft would be a stretch but I'd love to have a crack at that.

For the budget you are considering have you considered puchasing a recent dyne from a ski team complete ready to go? Could probably get a great deal on a 20ft twin ready to run. Alternatively they will have their motors for sale soon check the classifieds (search last years to get an idea of prices and who sells what, even PM them) and showskiers.com classifieds.

Unfortunately, as I'm in Australia, I've never driven a dyne. There is lots of good advice in this thread, worth a reread I think. I have driven a lot of outboard ski boats but not YET a dyne.

Greg

 

From the advice on this and other forums it looks like the best pair for me would be the 150XS Optimaxes. Merc makes a straight 150 Opti but it is a 2 star rating vs the 3 star rating of the 150XS Opti. Merc also makes a 1.5L Opti that weighs 375 each vs the 431 of the 150's but they do not give a star rating.

Verados would be cool but my boat is only 18' and for much less I could have the boat of my dreams that would work well with 150XS Optis. At the speeds I will be driving at I believe the fuel consumption differential between Verados and Optis is minimal.

No offense to the E-tech guys - those look like pretty good motors - but as earlier stated I am a Merc guy, and would rather sacrifice a small amount of what I want to keep the boat in the Merc family as that is what I am set up to deal with.

What really fires me up is ghind's post about what modern motors can do vs what I drove in the 70's. That 16' Dyne with the twin 115 Johnsons blew me away back then and as ghind pointed out it was probably 100 HP each at the prop. I would be happy with the same level of performance I had with that boat and that boat was propped at 19". I am thinking of propping the rig at 23". That would I think give me the same performance I had with the old boat considering I have an extra 100 Hp available and also help with fuel economy and noise at ski speeds. I am not going to tow a large number of skiers and am not interested in top end as I have another boat for that purpose.

You guys have convinced me that 2 strokes are the way to go. Thanks for all the input and that is why I came here for the expert advice.

 

You said that you had experience with a club 18 running twin opti's. What props does it run?

The reason I ask is because I have never seen or heard of a Dyne 18 or 20, twin, or single running 23 inch props.

The 115's you mentioned are geared different than a 150 opti I believe.

If I were you I would make it part of the deal with the motor dealer to let you try some different props.

There is a ton of prop discussion on this forum.


jim

 

Opti will use less fuel than a verado on that boat

I'm with Jim - not much point running one with 23" pitch props. If you want economy just put one 150XS Opti on it.

It isn't a go fast boat. Most teams seem to run 15 or 17" props on their multirigs. At least one triple used 13's on the outside and 14" in the middle (couldn't get a 13 counter rotation prop). Jim could tell you better than I can. I'd guess, I'd be happiest with with 19" pitch props or less for what you are describing you want to do. No point propping it with 23" props, the boat won't go fast whatever you do, isn't a go fast boat.

Wow would I like to drive it with 17" pitch props on it!

Greg

 

It looks like 19's would be the best. Should I consider a counter-rotating motor as one of the pair?

 

Yes, and mount them on 5 degree wedges, and choose your props carefully.

High performance props are not designed with ski boats in mind.

Most dealers have no clue about ski props. Any ski team knows more.

You need a prop with minumum rake and cup. A proper 17 will give more stern lift than a 19 which you will need in spades. The bottom of the line props usually come the closest.

I have mine custom modified which I will share with you if you like.

jim

 

It looks like 150 Optis will do everyting I want. I have done extensive research on Merc's website and the fuel economy at the speeds I will be going at the DFI motors are actually slightly better than the Verados.

Where do I get 5 degree wedges?

It would seem that a 17 or a 19" stock aluminum prop would be the best and affordable option considering rake and no cup on stock props.

Merc is supposed to come out with a very light 3L 150 4 stroke with normal controls this fall and I am interested in it as well. Maybe it will be really quiet.

But then again after reading all the opinions here the 150XS Optis is the way to go. For now.