Custom/Hybrid Cutting weight off a triple behemoth!

[Nuclear Cowboy]

So I pulled this out of my donor STX the other day and it is gonna end up in a SX/SXi hull. It was heavy enough just lifting it out of the hull, but hauling it up the stairs into my 3rd-floor apartment was a near-death experience! It was at this point that I came to the unfortunate realization of how it will handle being stuffed inside of a tiny little SX... So before I tear thing thing apart, I want to try and identify any possible weight-saving replacements that I can use to put it back together lighter than when I took it apart.

I already know right off the bat I'm gonna need to get the manifold face milled down to fit it into the hull, so that will account for at least some weight loss... I know I'm definitely gonna go with that rad dudes engine cradle (which claims a 10lb loss from the stock plate) and I'm gonna block off the oil. Other than that, where else can I save weight? What are my options for the intake side? Pistons/rods? Crankshaft? Flywheel?

I don't know the aftermarket products like y'all do, this is gonna be my first build on a watercraft, so I appreciate all of the info I can get from you guys. But keep in mind I'm not at the point where I'm trying to shave a few ounces here or there for a few thousand dollars here or there. I'm trying to identify parts where I'm gonna be able to drop a significant amount of weight for the cost of the part(s)

Any suggestions??




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[CRJ]

do they make pipes for those? im sure the stock one weighs as much as the motor.

 

[Nuclear Cowboy]

the stock pipe is heavy as $hit! There is a mod that rad dudes offers for drying it out but youre still using the stock pipe. I'm not aware of a full aftermarket exhaust for it (but I haven't done much digging)

 

[4SeasonsPower]

Need to ditch those CV carbs.

 

[special fx]

I have the same motor in a FX-1 hull, it doesn't effect handling like you'd think. That said, lighter would be nice.

 

[Nuclear Cowboy]

Noted.

What kind of carb setup would you suggest? I've heard all kinds of stuff about different size aftermarket carbs on these 1100s and I've also heard that they can pack a lot of punch just sticking with the stock size...

I guess for this particular application I'm going for the lightest build possible without performance loss.


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[wanderer1]

Coffman's made one but if you find one it'll likely cost close to or more than what you paid for the donor. Gonna be a tough fit in that SX either way. Good luck

 

[fast superjet chase]

The triples only weigh 34 pounds more than the twins without the bed plate. I love my sxr with it handles like a dream.

 

[UneducatedFX1]

I'm pretty sure you can buy a lightweight flywheel for this engine, you can correct me but I'm pretty sure I saw it on a wave blaster 900 or 1100 light weight flywheel on it, I'll see if I can find the thread, I may be wrong but I'll take a look around for you, and I'll be checking in on this build sounds like an awesome project


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[Chris03HD]

Difference between an aftermarket an stock flywheel isn't much for what you're trying to shed overall, but it makes a big difference in how the motor reacts.

 

[OptimaRacing]

What type of riding will you be doing with the ski? If your running buoys or just playing around, the added weight will actually help the handling. Some 1100 parts can be found here:

http://www.optimaracing.com/index.php?route=product/category&path=349

 

[Nuclear Cowboy]

well I suppose I haven't decided yet what this ski is going to be primarily used for... I know I am going to be riding surf pretty frequently since I live right on the coast, but I have also been racing mx my whole life so I figure its only gonna be a matter of time after I get it built before I get the itch to race it :brap:

 

[Nuclear Cowboy]

in my quest to build the lightest triple ever, I came to the inevitable realization that the crank case and cylinders are the majority of my problem when it comes to weight. The heaviest single piece on the motor (just my assumption based on handling it) is the crank shaft. The flywheel doesn't seem like it is a significant source of weight because its mostly hollowed out. I wasn't considering the performance benefits of a lighter flywheel, but I will have to look into whether or not the weight cut is a noticeable difference. It is definitely encouraging to hear that the added weight could ENHANCE handling though, because my biggest fear was doing this project and getting it in the water only to find that I had built something too unstable to ride.