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Differnt motor swaps?? (move or delete if needed)

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SYKO

SYKO

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I tried search and couldn't really find what I wanted to know... As im always curious has anyone tried a newer motor swap (say new 4stroke in place of old 2 stroke) I understand that electrics would have to change but has it been done? I guess you would need to know if the hull would accomidate the engine or not. I was just thinking as I like my boat I got a lot (97 challenger) but thought how much more awesome it would be with a newer motor.

please move if needed I really didn't know if I could post this in the pinger forum or the 4stroke forum.
 
I know of a few... but generally it's not done... because the prices are expensive. you will spend a small fortune buying a donor ski for the parts... and then you will be swapping it into a boat/ski that's not worth as much.

You could simply sell your Challenger, and but a new(er) speedster (single engine 4-tec), and the difference in $$$ would be far less than buying the parts. And.... you would have better re-sale too !! Most people don't want a Franken-Boat.


The only one that I thought was "Worth it", was a 4-tec swap into an LRV. It's great family ski... but was only available with the 951. (personally, I hate that engine) So... in the end... it wasn't cheap... but now that person has a 4 seat ski, with a modern engine.
 
Oh no dought! I understand that I would be putting something back in something worth less. Honestly I love the size of my boat and wouldn't want anything bigger and ive never been into the newer speedsters... The only newer one I was interested in was the challenger 180 but even that is on the large size for what I want. I mean I got a 62 continental with 99 drivetrain... a 68 ford with newer drivetrain a 97 triumph Daytona 955 with a 2000 motor all of these have been updated with newer drivetrain to meet the needs I want because I don't want to change these vehicles because they are the way I want them. Kinda how I want to keep this boat the way it is, I understand that its worth way less then the ski the drivetrain came out of but im not looking for monetary worth. If it comes out being worth more to ME and my enjoyment then that's all I need.
 
Might not be quite as cool as your idea but how about mounting a bracket on the rear and hanging an outboard on that puppy? Would need to measure to be sure the outboard can be mounted deep enough to clear the hull but I expect it would.

It's not all about cool though, performance counts and jets burn tons of fuel. Outboards sip fuel in comparison b/c you eliminate the jet pump issues all together and I'd bet 100hp would set that thing on fire.
 
awww bummer!! what a terrible idea!! I cant stand open props they freak me out!! the whole reason why most of us even get these boats is because of the jet drive, I would like to keep it that way. I could have easily gotten a regular boat many times over the past few years but waited for one of these at the deal I wanted.
 
SYKO said:
Oh no dought! I understand that I would be putting something back in something worth less. Honestly I love the size of my boat and wouldn't want anything bigger and ive never been into the newer speedsters... The only newer one I was interested in was the challenger 180 but even that is on the large size for what I want. I mean I got a 62 continental with 99 drivetrain... a 68 ford with newer drivetrain a 97 triumph Daytona 955 with a 2000 motor all of these have been updated with newer drivetrain to meet the needs I want because I don't want to change these vehicles because they are the way I want them. Kinda how I want to keep this boat the way it is, I understand that its worth way less then the ski the drivetrain came out of but im not looking for monetary worth. If it comes out being worth more to ME and my enjoyment then that's all I need.
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MAN YOU'RE REPEATING ME VERBATIM!! I LOVE my Challenger, but agree that this engine is not quite up to par for the boat. For me, this boat is just the right size, but it's damn underpowered. That and I don't trust the 787. They are quite problematic IMO. Like you, I've been looking at different options to update the motor with and keep the jet pump. (I have seen this boat for sale with an outboard and thought it a travesty)
The biggest problem in converting is the length of the engine bay. The 787 is a [SIZE=.7]tiny[/SIZE] engine compared to most 4-strokes out there. Since 4 strokes need twice the strokes to achieve the same power, they need twice the pistons. Hence, a comperably powered motor would need to be at least a 3cyl. I looked at the 4-tec rotaxes and feel like we'd have to at least mod the fuel tank. Another interesting idea would be to put a rotary Mazda engine in there. The 13b is a pretty stout little motor. I've heard they make anywhere from 130 to 175hp w/o a turbo. A turbo would be rather hard to install as we'd need to water cool the exhaust. The 13b is a heavier motor than the rotax and it's probably as or less efficient than the 787. But I bet it's quieter, more reliable, and definitely more powerful. If I find one, I'd be damn tempted to get an old late-80's rx7 and just see what can be done. I'd even sacrifice the foot locker and replace it with a fuel tank to make this work. If I do that though, I might as well go with the Rotax as they're going to be more fuel efficient and are already configured for marine operation. The pump would have to be upgraded as well to either the seadoo 155, or even the sugar sand 7" pump. The little 140mm just isn't enough thrust. I believe it would be a worthwhile project as I love the challenger body style and lines. Also, it's probably the biggest boat my little diesel jetta can tow :)
 
Interesting topic! I've been looking something similar here. Explorer enginebay has more space longitudally than other seadoo boats of 90's, but height might be a problem. Keep us posted for any mods.
 
IDoSeaDoo said:
.... I LOVE my Challenger, but agree that this engine is not quite up to par for the boat. For me, this boat is just the right size, but it's damn underpowered. That and I don't trust the 787. They are quite problematic IMO. ...
Click to expand...

What are you talking about ?!? The 800 Rotax engine is NOT problematic. I have one in my collection that is 17 years old... starts with the touch of a button, and runs like scalded ape !!

Build it right... maintain it a little... and they run for a very long time.


As far as under-powered... I won't argue... but the single engine Challenger runs faster than a lot of small boats of the same age. If you need more power/speed... a speedster from the same year is the same $$$$, and is basically the same boat. So sell yours, and buy the twin.


Wile I agree that an outboard isn't even a viable option... I don't see the point of spending the $$$ to put a 4-tec into an old hull.

OK... old cars, with engine/frame/drive swaps is cool... but parts can be bought easy, and relatively cheap. But, unless you have connections with an insurance company... where you can buy a new-er 4-tec ski, with a damaged hull.... the price is just too high to buy the parts.

Then... after you drop a total of $10k into the boat... and a butt load of labor... it's still only going to be worth $4k... and it will be hard to sell. (I wouldn't buy it)


As I was saying before... you can sell your boat... and buy a newer 14.5' 4-tec speedster/sportster. Chances are... you will be into it for less $$$, and you will have something that can be sold to the general public after you are done.


OK... I'm not trying to sound negative, because I like projects, and mods.... but if you are going to swap in an engine... there are a lot of other engines that would be WAY easier, and WAY cheaper. I think the ideal swap would be a 13b mazda engine. Small, light, no expensive electronics, and are easy to get.






Oh... last thing... to put a 4-tec in... and to take advantage of the power... you would have to also use the bigger pump. AND... it would be major surgery to cut the intake out of your hull, to feed it more water. Unlike car surgery... grafting fiberglass, in a stress area NEVER works out. (welding is easy)
 
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SYKO said:
awww bummer!! what a terrible idea!! I cant stand open props they freak me out!! the whole reason why most of us even get these boats is because of the jet drive, I would like to keep it that way. I could have easily gotten a regular boat many times over the past few years but waited for one of these at the deal I wanted.
Click to expand...

I figured you'd say that, these boats might look pretty ugly with an outboard hanging on the back as well, hard to say.

In all my 50-some years of boating though, I've never gotten anywhere close to being sliced up by a prop. Maybe b/c I stay in the boat unless I'm at the end of a rope and the engine is off if anyone else is. Propped boats far outperform jet boats though, top speed and fuel consumption. It's probably safer than walking down the side of the road on a sidewalk, IMO.

Draft is the big plus. I like the jets for their shallow draft, some rivers are just too shallow to run a prop. The jet is also necessary for small craft like jet skis but for boats any benefit disappears in deep water and operating cost becomes the issue.

Fortunately, the reman replacement engines are far cheaper than outboards but these engines don't last as long, mainly due to the heavier loads of the chosen propulsion system.
 
As I said, I like the shape/style of the Challenger, and I don't want to buy an SUV to tow a bigger, newer boat. I thought about the speedster, and while they are perhaps the most fun vehicle I've ever driven, they eat entirely too much fuel. Hell, MY boat eats too much fuel. I've seen hull damaged 4-tecs out there for several grand that still run. It would be worth it TO ME to install a newer, quieter, more efficient engine and make this the perfect boat. I don't foresee a reason of why I would ever sell it in the near future.
I must not have the golden touch with these engines, b/c my boat 787 won't spool to 7k. I'm missing about 500rpm and it's lacking power, acceleration, and top-speed, and it always seems like there's one problem after another with the boat's engine. In the end, I feel that it's just not enough engine for this size boat. I'm working it too hard. Plus, the raves seem to go out every year. I bought a brand new set from SBT a year ago, and one of them started puking that black goo mid-season. I feel that it would be less trouble stuffing another engine in there than chasing 787 problems one at a time.
Now, I'm not saying the 787 is a bad engine. It's great in the X4s. Hence I own two of them. They seem the right fit in a jet ski. Not a boat. Maybe dropping a better engine in there isn't "financially feasible", but I think it would be a fun project, and it sure would make me happy :)
 
FinnExplorer said:
Interesting topic! I've been looking something similar here. Explorer enginebay has more space longitudally than other seadoo boats of 90's, but height might be a problem. Keep us posted for any mods.
Click to expand...

In your case, I'd drop a 787 in there. You'd have to do some minimal mods to fit it in there, and since it's leaning to one side, I don't think height would be an issue. Easy way to gain 25hp ;) You will eat quite a bit more fuel however.
 
IDoSeaDoo said:
In your case, I'd drop a 787 in there. You'd have to do some minimal mods to fit it in there, and since it's leaning to one side, I don't think height would be an issue. Easy way to gain 25hp ;) You will eat quite a bit more fuel however.
Click to expand...

With my hours out there, it pretty much doesn't matter how much the fuel costs :D Even though the fuel equal to your 91 octane costs ~1.70€(6.46$/gallon did I get my math right?) per liter here. I've been looking for natural aspirated 4-tecs but haven't come by any so far. Most insurance companies don't give insurances for jetskis here, so i would think there's crashed ones for sale...
 
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Glad this thread is getting some responses, im new to boating in general but experienced in doing major mods to machines and vehicles to work. Im also proficient with fiberglass repair and modding (couple years working in a corvett only shop then a marine hull repair place) Im interested in doing a engine swap not now but later when I have more experience on the water. Then I would weigh all the options, I do like the rotary option as I already done one of those in a body dropped mazda pickup, but I wouldn't know where to start as far as connecting the drive on that, if I did a swap is would be another jetski style engine and gear. I still don't know enough about the newer motors to start thinking about it yet, I also really dont worry about cost if and when the time comes I can guarantee I will only spend what I want to spend.
 
This company makes rotary engines, they bought OMC's designs and have converted some jet skis apparently:

http://www.freedom-motors.com/

Funny thing is, the OMC design was actually manufactured by Curtis Wright, for OMC. I guess the stern drive was OMC's, later OMC drives after the stringer model, was the Cobra, wasn't a very good drive.
 
grinditout said:
your upgrade would be a 951.
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Meh... not much of an upgrade. It would guzzle even more gas, be just as loud and (from what I hear) be more problematic. The only benefit would be the added power. However, I think I would cry watching my gas needle drop. Anyone out there have a 4-tec that's been wrecked but still runs?
 
Again. Have you looked at the newer 14.5 foot 4tecs 2003 ish model. Same size and seating arrangement as yours just nicer with 4tec all set already! They are cheap, way cheaper than a swap. Plus if you're worried about weight for towing, swapping a 4 tec and its electronics plus bigger pump and intake and closed loop cooling, you are more than double (close to triple) the weight that old 787 and its electronics are. So you are adding extra weight to tow regardless why not just upgrade?

If you absolutely must have a 4 stroke skip the 4 tec. Go rotary 13b. Simple. It will just be really loud since you can't water cool exhaust because it has to be hot to heat manifold to make it run right.
 
docster said:
Again. Have you looked at the newer 14.5 foot 4tecs 2003 ish model. Same size and seating arrangement as yours just nicer with 4tec all set already! They are cheap, way cheaper than a swap. Plus if you're worried about weight for towing, swapping a 4 tec and its electronics plus bigger pump and intake and closed loop cooling, you are more than double (close to triple) the weight that old 787 and its electronics are. So you are adding extra weight to tow regardless why not just upgrade?

If you absolutely must have a 4 stroke skip the 4 tec. Go rotary 13b. Simple. It will just be really loud since you can't water cool exhaust because it has to be hot to heat manifold to make it run right.
Click to expand...

What? There's a 14.5' boat with a 4tec out there?? WHERE? Please give me the name of it or a URL. The last 14.5' boat seadoo made was the Sportster LE and it came with a 2-stroke 951 DI.
 
Harshness for the day:

The 787 is the Hipo 720--rock F'ing solid engine meant to be ridden hard and put away wet. If you want a boat that has some ballsack get one with twins. Conversion to a 951, Mazda's rotarys, too much BS. 787 TWINS plain and simple, get one before one gets you.

And in the words of the Doc-- "That's my story, and I'm stickn' to it."
 
See link >

http://www.seadooforum.com/showthread.php?27754-97-Challenger-motor-upgrade-to-a-V6

Sums it up in the first post>

"OK... I'm all for unusual projects... but I need to get this out of the way first. It's a dumb project"

Cost vs Value

And he hit the nail in the second post>

"If you want more top speed out of your boat... then it's simple. You need more velocity out of your pump"

You will have to rework the hull, to get a pump in for a larger engine, that is why I said a 951, not that, it made any sense, just would be the limit, in my mind vis-a-vie pump upgrade.

cash in the old, get the new, utopia.

http://www.boatingmag.com/boats/sea-doo-utopia-205
 
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:( Yea, I already knew about this one. Aside from being considerably uglier than the 97 Challenger, they did away with the little front seat area. My friends and I like lounging on it or even riding there. Yea, it's bumpy and intense, but that's the point! Also that boat weighs an extra 200lbs. I'm already pushing the towing capabilities of my car with the 1260lbs challenger. If my boat came with that 155 engine, all would be well :) I'll probably end up getting one eventually and hoping I'll get used to the stupid alien look of it. Or maybe I'll just buy an SUV and buy the Speedster. Anyone know the fuel consumption difference between the 155 and the S/C 215 boats?

It really is too bad our Aussie friend gave up on that thread. I wonder if he ever put that moto engine into the Challenger...
 
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