Repower an X -- With What?

[Catigale]

Imagine pulling hard on a 1600cc 4 cyl engine, while tiered and frustrated,

We used to pull start our 1600cc VW (lower compression, but still about 8:1) with our belts on the generator pulley all the time.

The 50 pulls starts pretty easily but the kickback is bad. One of the problems is the cord they give you for this is way to stretchy imho...Ive tried it with a stiffer cord and it is pretty easy.

Of course, EFI is a part of this - I bet pull starting a carbed engine sucks.

[Mark Chamberlain]

New V90 is only 62 lbs heavier than the 50, same fuel use at same speed.
check into this motor

[Terry]

What is a V90????
Is it a Merc, Honda, Evinrude or what?
I can't wait for my Honda 50 to expire and when it does the replacement has to get the boat up on plane or else I won't buy it. The boat is a hybrid and unless it gets up on plane one does not truly experience the powering side of the hybrid. Power to weight ratio will also be a consideration, if the weight of the 90 is the same as a 75 then I'd take the 90 for the same weight. But I suppose it will be some time before my old dependable Honda dies. Maybe I should poison it!

[jasper]

"I hope from your mention of a speed with the ballast tank 1/3 full that you don't operate the boat that way"
It was a one time only. After the new motor was installed and I was returning the boat to the mooring. Water was shallow, so I only partly filled the tank. Bringing it back tot he mooring, I opened up, on a straight course, sails were down. As I keep the tank full on the mooring, we always have lots of ballast while motoring

[jasper]

My one thing I learned is to read the engine manual first. It says only full-throttle after 2 hours. My saving grace was that it had been run for an hour or so in the tank by the dealer and my 20 second burst didn't do any damage.

[bastonjock]

i havent yet tried to handstart my Yam 50 big foot but after reading catgails post,ill get a new starting rope first

[Bobby T.-26X #4767]

What is a V90????
Is it a Merc, Honda, Evinrude or what?

you're talkin' 'bout the New! Honda VTEC 90...right?
the spec page says: 359# w/out prop weight.
the Honda 50 is just over 200#, so the V90 is 160+# over the 50.

however, i, too, believe that the New! VTEC 90 is the preferred option for a Mac versus the Suzi 70 (which is about the same weight).

it's the cost that gets me...things are really expensive these days

Bob T.
"DāBob"
'02X w/ '04 90-TLDI (14" x 11 pitch)
Dinghy Motor: '06 2.5-Suzuki

[Dimitri-2000X-Tampa]

I just can't sit quietly with this misinformation being flung around. The 26X planes just fine with a 50HP, does not take all 50HP to do it either so I'll bet it would plane with 40HP also. It is a planing hull and well exceeds both hull (displacement) speed and semi-displacement speed with the 50. The reason the Mac sits a little nose higher than speedboats when it is planing at 15kn is because of the nature of the hybrid hull, ie, it is not a "pure" planing hull and has less of an angle (to horizontal) behind the CB trunk versus in front. With a larger motor like a 90 for example, the boat goes faster, comes out of the water more (ie, a faster planing speed) so that it rides on the flatter portion of the hull further aft. Its only natural for the bow to come down a little further now because there is less angle on the hull where it is contacting the water. You could simulate this behavior with trim tabs on a speedboat.

I was in my friends Yamaha jetboat last weekend with 270HP (2 jetdrives), it doesn't put its nose into the sky at all (even if you holeshot it) because the thrust is higher up on the transom than a conventional propellor powered speedboat (plain old physics here). So, even close to 60mph, the nose doesn't "come down" like some people here seem to think is the definition of planing. It doesn't come down because it never went up in the first place. The boat just raises out of the water uniformly (same nose angle) as the speed rises.

I want a bigger motor just like all the other 26X oldtimers, but its not to plane the boat, its to make it go faster. The problem is that my Mercury 50HP 4stroke Bigfoot still does a terrific job, carbs and all. So, I'm just not in the mood yet to fork out ~8 grand to be able to go 5 knots faster, especially when I usually prefer to go slower and sail. By definition, a 4 stroke motor is typically going to last quite a bit longer than a 2 stroke. Mine has been used for several hours a month for over 7 years.

[vkmaynard]

Actually the Mac struggles (WOT) to get to 17.5 MPH on a Honda 50. I seriously doubt it could make 15 knt on that motor (19 mph), at least not on our boat. As a guess, planning is probably around 20-22 mph on a Mac. If anyone out there has kids an wants to go wakeboarding, then get a bigger motor. We take our kids and neighbor kids often and just barely get them up and around. It needs another 4-5 mph to get the wakeboard up to 20 mph.

It's all a matter of choice and $$$

Victor

Can you do this with a Honda 50?? Billy running 30+ mph with his Suzuki 140. Notice the airborness after hitting waves.

[Duane Dunn, Allegro]

Dimitri,

Not to start the age old argument yet again, but you really need to go out on an X with a bigger motor to understand that my (and your) X is not planing at 15 knots. All it takes is that one time to clearly feel the bow drop and the boat release from the hole and you will know for sure what planing in a X is.

I experienced it for the first time this last Tuesday and it was very pronounced. The three of us in the cockpit all felt the same thing and looked at each other and nodded our heads as we all felt it happen.

All it takes is the seat of your pants to tell when the boat comes up onto a true and full plane. All the time spent at above hull speed but below 18 knots is purely plowing, semi displacement, if only I could get enough weight in front of the hole stuff. The nose is hanging out there but it just can't lift the butt out of the hole. You're dancing on the edge but you never make it.

In Dano's boat with the 90hp motor the transition to planing was clear as day and it has never happened in my X even though I regularly hit 16 knots at WOT when we are out playing on the lake.

I know 25 more ponies would get me there, but my Tohatsu 50 is so bullet proof I doubt it will ever die and that is the only thing that likely will ever force me to replace my motor.

Jasper,

Glad to hear you keep the tank full. With your smaller motor you might want to spend more time under power with it empty. 95+% of the time we spend under power is with the tank empty. The boat handles great with the tank empty at all speeds, we only fill it to raise the sails or when the seas are over 4'-5' and close together. The extra weight then keeps the boat from launching off the wave crests.

I prefer an empty tank around the docks, the boat stops and turns faster when it is light. I have found the extra ballast weight does nothing to counter wind around the dock. We always dump our ballast (if we have any to begin with) on the way back to the launch. Why have yet another thing to wait for once the boat is on the trailer. It takes long enough as it is to get the mast and gear ready for the road.

vkmaynard,

That picture is great, it shows very clearly something else that I noticed last week when we were planing, the spray pattern. The bow spray was much more aft than I had ever seen before in my boat. It was a tall wide spray that was way back next to the cockpit, just like in your picture.

[Dimitri-2000X-Tampa]

The bow spray was much more aft than I had ever seen before in my boat. It was a tall wide spray that was way back next to the cockpit

Your observation adds creedence to my statement about riding further back on the hull. At 15-16 knots, your bow spray is further forward but it is still bow spray which is the definition of planing, versus plowing which creates bow wave instead of spray. Wadr, I think what you are "feeling" in the seat of your pants is the additional acceleration that the larger motor has over the 50.

[Duane Dunn, Allegro]

What I felt was a clear drop in the bow as we fully climbed out of the hole, something I've felt 100's of times before in ski boats but never before in a Mac. The acceleration wasn't any more dramatic than with a 50, the boat still took some of time to build speed but as it climbed out of the hole there was noticable change in the attitude of the boat. It became flatter and was able to build even more speed as it released from the hole. It's behavior was about as classic as it get's for a hull coming up onto a full plane.

Plenty of non-planing boats put out bow spray with out being on a plane. Throw enough horsepower at any boat and it will get past hull speed and throw spray, that doesn't mean it is planing.

My point in mentioning the spray is that never before with my boat had I seen spray so far aft. It looked just like the picture of Billy's boat which at 30 knots is clearly planing. Until the aft part of the hull lifts out of the hole (and apparently the spray moves aft) these hulls are not on a full plane. Call it what you like, semi planing, etc., what you get with a 50 hp is not a full plane. It takes a bigger motor to really get these boats skipping along on the surface.

[Phillip]

I don't want to get into the discussion re size of a motor.

When it comes to Brand, then I would urge you to at least get a copy of the DVD on the Evinrude E-Tech, watch it, so you understand the advances Evinrude have made in the 2 stroke field.
If my memory serves me correctly, there are 5 major differences.
If you can't get the DVD (Evinrude distribute it 'free' down-under) then PM me and I will try and run a copy and post it to you snail-mail....shouldn't need to tho....it must be available in your country.
Cheers
Phillip

[Catigale]

On repowering - check your local ordinances in case some of your favourite spots have 2 stroke bans in the works - it would be bummer if you repowered only to find you were banned. I think some of the lakes out West were contemplating/executing 2 stroke bans?

[beene]

I still firmly believe that it is not only power, but the angle of the transom that keeps the Mac in a predominantly nose high attitude. This also affects the spray pattern oberved by some.

In that pic of XX, it would appear the boat has just hit a wave, causing it to look as though the spray pattern is far aft and the front half of the boat is well out of the water. I suspect that it would not have looked this way had the pic been taken cruising along on flat water.

I can easily affect spray pattern with my M just by triming the motor up and down. With lots of weight up front, wedges, and trimmed full in, the spray pattern is far fwd. I can move that all the way to where XX has it in the pic just by tilting the motor up.

Look at how far back the center line of the wake is behind my M in this video, as well as the spray pattern being about half way down the boat.

Oh, and a tip for viewing videos online, pause it and let it fully load so it plays smoothly after you hit the play button.



The Bow is down, the boat is planing, I can see where I am going while sitting down, the boat stays fairly flat while in a mild turn, all good things IMHO.


G