lake-skater15
The sinker of skis.
- Location
- Modesto, CA
650s are turds and 750s are good but theyre heavier. Theyre better for racing not as much for freestyle. The 300sx hull is very light and short.
Custom/Hybrid Melmack's very unique 300sx build
- Thread starter Melmack
- Start date
650s are turds and 750s are good but theyre heavier. Theyre better for racing not as much for freestyle. The 300sx hull is very light and short.
Melmack
(Timothy)
- Location
- New Braunfels, TX
Thank you, too bad I didn't see that post a few min ago. That would have saved me from typing all this for the third time:
Read early on in the thread. I'm trying to keep the weight down. My new power plant will eventually be much lighter pound for pound than the heavy stock 700-800cc engines. If you put one of those engines in a 300, it ads 45+ pounds which changes the handling and lightweight feel of the ski. Also, If you read back, you will find that I plan on putting in a large motor very soon anyways for comparison and to measure the pumps capabilities.
I plan to eventually offer a similar design ski to what I'm testing with around 50-60 stock horsepower on the EPA CARB model with a "Competition Only" option that adds almost twice the power.
On a boat, more than a bike or car, weight makes much more difference because the surface tension of water creates far more drag than a road dose with wheels. Losing 50lbs in the drive train with relatively the same HP gives a significant power to weight ratio increase. This prototype is kind of like a Lotus sports car. It's lighter, still reasonably powerful but much more economical and should have a lower initial cost. It's like comparing a motorcycle with 100hp to a car with 200hp. The bike feels more powerful but in fact it is much weaker.
Also, this ski is designed to have an EPA and CARB approved motor so it can be sold in all 50 states. To do that with a ski after December 31, 2011 will require a very heavy, expensive and complicated 4 stroke motor like a Hydrospace. Try doing anything other than racing in one of those 380+lb skis. This ski is designed as a lightweight ski that will be mass produced and sold for the same price or even less than the current models. It will be light and nimble, fun for almost anyone. With the option of bolting on tons more power without turbos or expensive aftermarket engines.
The number one goal here is to meet the EPA requirements to continue the sport. There is only one company in the US that can produce and sell the engine we intend to use due to patents. They have plans to produce a specific size engine for other uses. Until we get some of these skis on the market or generate enough public interest, we cannot expect them to produce the perfect motor size we need. This hull works with the engine available for our prototype motor. The 300 motor we're using here for now is similar in size while slightly less powerful. It's a good fit to test the hull/drive line while we wait for a motor.
Read early on in the thread. I'm trying to keep the weight down. My new power plant will eventually be much lighter pound for pound than the heavy stock 700-800cc engines. If you put one of those engines in a 300, it ads 45+ pounds which changes the handling and lightweight feel of the ski. Also, If you read back, you will find that I plan on putting in a large motor very soon anyways for comparison and to measure the pumps capabilities.
I plan to eventually offer a similar design ski to what I'm testing with around 50-60 stock horsepower on the EPA CARB model with a "Competition Only" option that adds almost twice the power.
On a boat, more than a bike or car, weight makes much more difference because the surface tension of water creates far more drag than a road dose with wheels. Losing 50lbs in the drive train with relatively the same HP gives a significant power to weight ratio increase. This prototype is kind of like a Lotus sports car. It's lighter, still reasonably powerful but much more economical and should have a lower initial cost. It's like comparing a motorcycle with 100hp to a car with 200hp. The bike feels more powerful but in fact it is much weaker.
Also, this ski is designed to have an EPA and CARB approved motor so it can be sold in all 50 states. To do that with a ski after December 31, 2011 will require a very heavy, expensive and complicated 4 stroke motor like a Hydrospace. Try doing anything other than racing in one of those 380+lb skis. This ski is designed as a lightweight ski that will be mass produced and sold for the same price or even less than the current models. It will be light and nimble, fun for almost anyone. With the option of bolting on tons more power without turbos or expensive aftermarket engines.
The number one goal here is to meet the EPA requirements to continue the sport. There is only one company in the US that can produce and sell the engine we intend to use due to patents. They have plans to produce a specific size engine for other uses. Until we get some of these skis on the market or generate enough public interest, we cannot expect them to produce the perfect motor size we need. This hull works with the engine available for our prototype motor. The 300 motor we're using here for now is similar in size while slightly less powerful. It's a good fit to test the hull/drive line while we wait for a motor.
Last edited:
Melmack
(Timothy)
- Location
- New Braunfels, TX
On another note: Just read some updated tuning info from Group K. Sounds like I have the pop off close but could lower it just a bit to fix the need for the choke at times. Then, I'll have a better idea where the jetting should be. I'm pretty sure I'm a bit too small on the bottom. Not so sure on the top. From what your saying WFO, i'm planning on looking for a smaller jet but my top screw isn't out much right now and it feels good once up to speed.
Melmack
(Timothy)
- Location
- New Braunfels, TX
Finally had a minute to see where my screws where. Top is 2 turns out, bottom is 2.5 turns out. So, at first it looks like I'm jetted too lean if anything but I think the screws are adjusting for the high pop off. I'll change the spring to the next one down. Hopefully that will allow me to turn the screws in about 1 turn each. If so, I'm dead on with the stock 1100 jets.
- Location
- Brentwood CA
ohh alright. thank you very much for the response!
Melmack
(Timothy)
- Location
- New Braunfels, TX
I think he was just trying to sum up what I'm thinking when I took on this project. Thanks for the interest.
Maybe you where referring to the ski itself. The 300 is way shorter than a 650 or 750. Plus its incredibly light weight. This makes it jump and pop out of the water much easier than the 300lbs 650 and 750s. It's main drawback is lack of power. Several guys here have modified this hull for more power because its basic dimensions fit the sport better than the long, skinny race style skis of today. It's a better starting point than say a heavy and very long 750sxi. You will find very few if any SXIs out there being moded for freestyle for this reason. The 650s on the other hand, where originally fitted with a tiny 28mm carburetor witch killed their reputation. A well tuned 650 can be surprisingly fun on flat water and surf with little modification but they are still heavy in comparison to a 300.
Maybe you where referring to the ski itself. The 300 is way shorter than a 650 or 750. Plus its incredibly light weight. This makes it jump and pop out of the water much easier than the 300lbs 650 and 750s. It's main drawback is lack of power. Several guys here have modified this hull for more power because its basic dimensions fit the sport better than the long, skinny race style skis of today. It's a better starting point than say a heavy and very long 750sxi. You will find very few if any SXIs out there being moded for freestyle for this reason. The 650s on the other hand, where originally fitted with a tiny 28mm carburetor witch killed their reputation. A well tuned 650 can be surprisingly fun on flat water and surf with little modification but they are still heavy in comparison to a 300.
Last edited:
Melmack
(Timothy)
- Location
- New Braunfels, TX
Did some more testing today. Replaced the brass spring with the next down. It still didn't seem right. I decided to remove the boost bottle. The ski took off like nothing before. This made tuning much easier and it nearly removed all of the hesitation. I'm basically back to square one now that the boost bottle is gone. Going to try the bras spring again and go from there. Posibly going wit ha larger bottom jet. The top end seems right on despite everyone's recommendation. I'm at 1-1.5 turns depending on the pop off and bottom setting.
- Location
- Brentwood CA
swapmeet
Brotastic
- Location
- Arlington TX
That is one funny looking ski...LOL!!!! But it looks like it gets around good. Glad your tuning is coming around.
It sounds like you've got it tuned, but to answer your question on the the carb loading up. My wifes blaster is doing the same thing, and I can't get it tuned out with the screws.
Gonna drop the main jet down a size or two which should help from everything i've been reading.
It sounds like you've got it tuned, but to answer your question on the the carb loading up. My wifes blaster is doing the same thing, and I can't get it tuned out with the screws.
Gonna drop the main jet down a size or two which should help from everything i've been reading.
Melmack
(Timothy)
- Location
- New Braunfels, TX
Yea, carburetion is an art. I used to be pretty good at it but I've lost the touch. Pluss, there are nos specks for this build anywhere. Hopefully I'll have it running smooth for lsfr. You'lle have to give it a go. I want as much feedback as possible.
Update on the special motor: Looks like I won't get my hands on my prototype engine until late summer at best. Until then, I'm probably just going to ride this thing like it is. It's a lot of fun and gets big air with ease.
Update on the special motor: Looks like I won't get my hands on my prototype engine until late summer at best. Until then, I'm probably just going to ride this thing like it is. It's a lot of fun and gets big air with ease.
Melmack
(Timothy)
- Location
- New Braunfels, TX
Turfed today. Looks really good. Just need to order my footstrap and dial this in and she's ready for some surf!
Liquid Graffix
liquidgraffix
- Location
- In the shop or on the water
um... pics! duh..... 
- Location
- wichita, ks
um... pics! duh.....
howd i know that was the next post coming...lol id like to see pics as well though
Melmack
(Timothy)
- Location
- New Braunfels, TX
It's just a turf job. lol.
I'll take several today after I get some work done.
I'll take several today after I get some work done.
- Location
- SoCal
I rode my 300 for the first time this weekend I have a 38mm Super bn 2 stage reeds 650 gasket mod and it dosent seem to have any where near the power that yours dose in the video. Do you think the pump swap helped that much? I have a different prop for the stock pump do you think it would be worth the effort of installing it?
Melmack
(Timothy)
- Location
- New Braunfels, TX
Well, the pump was very easy. And yes, I think it made all the difference. It's night and day different. It's not that difficult compared to the fx-1 to SJ pump job. Its all about the midshaft housing witch I made in one day. I can make you one for around $100 or you can do one yourself with a welder for $25. But I'm not sure I want to do more until I have proven it's reliability. I may build a conversion kit at some point. Right now the focus is getting this thing tuned and getting the Special engine from the manufacturer. Due to they're delays, I'm contemplating a different but more expensive source for now.
Melmack
(Timothy)
- Location
- New Braunfels, TX
Here's the turf. Since I promised the pics earlier. It's not cleaned up yet. Lots of glue overspray.
I know, I know, no footholds. I happen to prefer foot straps. They are adjustable, more comfortable, removable, cheaper, and they lock you in very easily. Of coarse, Our final ski will have something like the BOB and Rickter holds available. Those are my kind of holds. Also, the design will be set up so that all types of holds will work. Keep in mind that the 300 is just a prototype hull that will inspire our hull. We wont be making a 300 copy.
I know, I know, no footholds. I happen to prefer foot straps. They are adjustable, more comfortable, removable, cheaper, and they lock you in very easily. Of coarse, Our final ski will have something like the BOB and Rickter holds available. Those are my kind of holds. Also, the design will be set up so that all types of holds will work. Keep in mind that the 300 is just a prototype hull that will inspire our hull. We wont be making a 300 copy.
Last edited:
- Location
- Cheney lake Kansas
glue overspray???? what are you using ?
- Location
- SoCal
Turf looks really good makes me wanna re do mine in black diamond
Melmack
(Timothy)
- Location
- New Braunfels, TX
That's the cheap 'B stock' stuff from Hydro. It's all I use. One sheet dose about 2 skis. Love it. Used some medium padding for the bed and rails.
The adhesive is 3M 90. I also use Jasco adhesive primer about 15 min before applying the spray. The trick with 90 is getting the timing just right. If so it goes on very thin and super strong. Less messy than contact cement too.
The adhesive is 3M 90. I also use Jasco adhesive primer about 15 min before applying the spray. The trick with 90 is getting the timing just right. If so it goes on very thin and super strong. Less messy than contact cement too.
Last edited: