Has anyone tried 3d printing a hull?

HarryConnolly

HarryConnolly

Location
West Roxbury, Boston
Sparkplug said:
I ride at least 5 hours a week. All year long. Either a 701 waveblaster. Or a 1100 xfr. In the sac river. Used to ride surf quite a bit also.

I do all my wrenching and machine work. I've bored my own cylinders. Rebuilt starters. Pressed apart, rebuilt, and trued my own cranks. Lightened my own flywheels. I don't pay for any type of work unless it's a time issue. Have I wasted some money? Hell yeh. Made 100x more tho.

My secret? Don't have kids!! Also, have a chill job that doesn't stress you out and allows you time to enjoy your hobbies instead of making you dread them.
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A good portion of my buddies have said if I consider kids, I should just slam my nut sack in a window sill. Apparently the pain up front is better than dragging it out for 18 years lol.

in retrospect, the ski’s I’ve ridden and the time I’ve spent was no more than 20-30 minutes if that at a time. Thinking about that, 5 hours is a poop load of time. How often are you rebuilding a motor? I have no ski motor experience. I’ve rebuilt a poopload of 2 stroke dirt bikes.

I think I’ll have to learn how many hours these things can take.

Beer broke every single toy I’ve owned, I like your style.
 
kevbo

kevbo

Location
dfw
If you keep the RPMs modest and the exhaust port narrow the typical overhaul interval is 300 hours. A Yamaha 650 turning 6000 RPM will probably run over 1000 hrs. The other extreme would be a superstock race engine. Its wide exhaust ports and 7800 rpm will need new pistons at 10X the normal rate. You can burn a piston on relatively mild setups at any time.
 
Sparkplug

Sparkplug

Location
Red Bluff CA
HarryConnolly said:
A good portion of my buddies have said if I consider kids, I should just slam my nut sack in a window sill. Apparently the pain up front is better than dragging it out for 18 years lol.

in retrospect, the ski’s I’ve ridden and the time I’ve spent was no more than 20-30 minutes if that at a time. Thinking about that, 5 hours is a poop load of time. How often are you rebuilding a motor? I have no ski motor experience. I’ve rebuilt a poopload of 2 stroke dirt bikes.

I think I’ll have to learn how many hours these things can take.

Beer broke every single toy I’ve owned, I like your style.
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I do my dasa per the schedule.

Everything else. When it blows it blows. Like I said. Beer has done the most damage. Whether is caused me to suck up rocks. Hit rocks. Detonate my engine. Overheat or hydrolock. 9/10 times its cause I'm stupid after I drink. If I just rode my skis rec. They would never break.

If you really wanna know if your a good ski builder. Go huck barrels and back flips in surf, and let the ski get taken from you, flipped, get it back, and if it stoll starts. Your the man


Edit; today I noticed my pisser were hotter than Normal. Beached. And checked it. Sure enough. My water bar had blown 2 npt plugs out and was spraying into the hull. Could been a costly mistake if I didn't know the ski and catch it in time
 
Big Kahuna

Big Kahuna

Administrator
Location
Tuscaloosa, AL
kevbo said:
If you keep the RPMs modest and the exhaust port narrow the typical overhaul interval is 300 hours. A Yamaha 650 turning 6000 RPM will probably run over 1000 hrs. The other extreme would be a superstock race engine. Its wide exhaust ports and 7800 rpm will need new pistons at 10X the normal rate. You can burn a piston on relatively mild setups at any time.
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You may have missed where he mentioned an XS1400................ Not going to get 20% of your 300 hours out of that motor!
 
wikstromm

wikstromm

Washed up hillbilly
Location
SE
Im 6.5 and I have no trouble that my ski (sf circus) is to small, sure it rides nose high at low speed but thats just need more agressive riding to get that sorted out.
When you are tall you need to work that body in other ways than the shorter dudes, this exact thing replicates for me to riding motocross snocross etc
 
kevbo

kevbo

Location
dfw
Big Kahuna said:
You may have missed where he mentioned an XS1400................ Not going to get 20% of your 300 hours out of that motor!
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I was generalizing since I've never heard anyone in the PWC world talk about engine lifespan and failure modes. Smaller and slower turning engines can last a long time. Bigger and/or faster ones won't. Rotax recommends 300 hrs between overhauls for their 580 aircraft engine and there have been many 800XPs last that long. Superstock SXR800 come apart at around 1/10 that time. I doubt the makers of giant freestyle engines do much long term testing. Its much more profitable to just produce one and sell it to a kid who will never know much about it.
 
JC-SuperJet

JC-SuperJet

Location
Texas
Group K did have a rough maintenance schedule relative to Piston Speeds:

4000+ fpm – Completely unpredictable life span of crankshaft components
3700 fpm – Crank life can predictably be 20-35 hours
3500 fpm – Crank life can predictably be a full season of use
3300 fpm – Crank life is predictably 2-3 seasons of use
3100 fpm – Production unit range, predictably 4-5 seasons of use

Can monitor Piston Health with periodic Compression Readings.

www.omnicalculator.com

Piston Speed Calculator

Our piston speed calculator calculates the mean speed a piston moves in the cylinder bore.
www.omnicalculator.com www.omnicalculator.com
 
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Sparkplug

Sparkplug

Location
Red Bluff CA
I have well over 100 hrs on a dasa 1100. And I got it used from a buddy. All I've done is 2 sets of wrist pin bearings. 2 sets of crank seals. And gaskets every 50 hours. It's never shown any serious signs of wear in the 3rd season of me owning it. I run redline 2t.

I also have 3 rotax powered aircraft. The tbo is 300 hrs as mentioned. At 6500 rpm. But it's pretty well known that they typically just need to be decarboned and are good to go for another 300
 
WFO Speedracer

WFO Speedracer

A lifetime ban is like a lifetime warranty !
Location
Alabama
I have a friend that tried to get an extra season out of his Jetworks stroker motor , it blew up under the Kowaliga bridge on Lake Martinn after one of our freerides. it came apart so hard it put a dent in the bottom of the hull , those recommendations for crankshaft rebuild and replacement intervals will bite you in the ass if not followed.
 
Sparkplug

Sparkplug

Location
Red Bluff CA
WFO Speedracer said:
I have a friend that tried to get an extra season out of his Jetworks stroker motor , it blew up under the Kowaliga bridge on Lake Martinn after one of our freerides. it came apart so hard it put a dent in the bottom of the hull , those recommendations for crankshaft rebuild and replacement intervals will bite you in the ass if not followed.
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Did that friend disassemble his engine every 50 hours and inspect the parts per jetworks spec? Put the crank on v blocks and check runout? Ring gaps and piston clearances? Or did the guy just run the engine for seasons with never opening it up? It only takes a few hours to pull an engine out. Apart. Check it. And put it back in fresh. I don't see the need to replace any large hard parts if they are still within the spec specified by a manual. It couldn't hurt tho I imagine. Besides the wallet.

I overheated the ever living piss out of my dasa yesterday. Prob good 40 seconds of run time to get back to safe spot could shut off, with no water at all coming out of the pissers. Not good
 
WFO Speedracer

WFO Speedracer

A lifetime ban is like a lifetime warranty !
Location
Alabama
WFO Speedracer said:
I have a friend that tried to get an extra season out of his Jetworks stroker motor , it blew up under the Kowaliga bridge on Lake Martinn after one of our freerides. it came apart so hard it put a dent in the bottom of the hull , those recommendations for crankshaft rebuild and replacement intervals will bite you in the ass if not followed.
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Reading is fundamental, and completely voluntary it seems.
 
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