300sx

[WFO Speedracer]

Ok, you two do two different things, and let me know how it works out and I'll decide to copy you or do something else :biggrin:



That's why people pay the money they do for these hulls. The hard part is done. In the end $3500 is a very reasonable price for what you get.

I mean if someone were to go out and spend $200 on a 750 hull (or SN hull for that matter), $200 on a 300 hull, $100+ on glass supplies, $50 on foam, $100 on footholds, then $500 on paint, you'd have over $1150 and tons of labor in something that might be completely worthless.

Or you could do what I did, spend $75.00 on a 300SX hull,$0.00 on a 750 hull $100.00 on glass, epoxy and supplies and $85.00 on paint, splash a mold out of a 650 pump tunnel, put the mold into the 300SX and build a new pump tunnel and go ride.

 

[tnj4life]

Gotta get that motor in their some how.


I'll be the first to tell you that I know nothing about a 300sx, never even been around one in person. I know i used a conversion plate for our js440 when we went the 750 route. The 300sx must be different. I thought maybe you were moving the motor back for a setback pump for backies, didnt realize the 300sx is much different motor mount location wise.

 

[Cannibal]

So I did some measuring. My X2 trim from flange that bolts to the pump to the end of the nozzle measures 10". Cutting the hull flush with the back ride plate mount leaves the nozzle protruding 4". If you mount that even with the back of the bond line on the 300, you still have 4" hanging out the back. If you left the 750 bottom in one piece until in front of the motor mounts, you end up close to the fuel tank, but it would work for some exhausts. I was hoping to use my 750 limited pipe, and it doesn't leave enough room in front of the engine for that. So, I'd have to move back my engine another 2", which means it will make 6" of nozzle protruding past the ski. I mocked it up and there is just no way 6" protruding is good. Looks like a PITA to even get on the ski.

So, I'll probably be mounting mine like above, where the back hole of the ride plate mount is even with the back of the existing 300 hull, not the bond line. The nozzle will stick out 4" past the hull, but only 3" past the bond line (hull to bond line is only 1") and I'll have to use custom engine mounts that move the engine toward the pump by 3", giving me the same 2" I was looking for above (because I'm setting the pump 1" forward than the above measurements).

If anyone is using a regular 750 nozzle, they are only 7.5" not 10". So more can be done with them.

 

[tnj4life]

Another question. Why not go with a yamaha powerplant? A 61x cyl/62t bottom 701 would give that small hull alot of snap. Its not too much trouble to put one in a js.

 

[Brian_216]

Im also running an X2 nozzle. I guess Ill be leaving my pump where it is... I cut the bottom of my hull tonight, right through the rear mounts. How did you get the bulkhead cut out? and the tray area? Im kinda stuck here now with the bottom cut up. that and removing old turf from my revs and tray.

 

[driftmaster]

Gotta get that motor in their some how.


I'll be the first to tell you that I know nothing about a 300sx, never even been around one in person. I know i used a conversion plate for our js440 when we went the 750 route. The 300sx must be different. I thought maybe you were moving the motor back for a setback pump for backies, didnt realize the 300sx is much different motor mount location wise.

Yes to get the motor back and just wanted to clean it up and I wanted stronger mounts.

So I did some measuring. My X2 trim from flange that bolts to the pump to the end of the nozzle measures 10". Cutting the hull flush with the back ride plate mount leaves the nozzle protruding 4". If you mount that even with the back of the bond line on the 300, you still have 4" hanging out the back. If you left the 750 bottom in one piece until in front of the motor mounts, you end up close to the fuel tank, but it would work for some exhausts. I was hoping to use my 750 limited pipe, and it doesn't leave enough room in front of the engine for that. So, I'd have to move back my engine another 2", which means it will make 6" of nozzle protruding past the ski. I mocked it up and there is just no way 6" protruding is good. Looks like a PITA to even get on the ski.

So, I'll probably be mounting mine like above, where the back hole of the ride plate mount is even with the back of the existing 300 hull, not the bond line. The nozzle will stick out 4" past the hull, but only 3" past the bond line (hull to bond line is only 1") and I'll have to use custom engine mounts that move the engine toward the pump by 3", giving me the same 2" I was looking for above (because I'm setting the pump 1" forward than the above measurements).

If anyone is using a regular 750 nozzle, they are only 7.5" not 10". So more can be done with them.

Its how I saw things. Cut that shaft. To have room to run any pipe you have to get the motor back. I want the weight centered. I am thinking of cutting a inch or to off the back atm. After thinking and reading the post, it would be easier if ur really want to set back the pump farther. The bulk heads line up the way Im doing it, makes easy to glass back.

Another question. Why not go with a yamaha powerplant? A 61x cyl/62t bottom 701 would give that small hull alot of snap. Its not too much trouble to put one in a js.

Kawi parts are CHEAP!!!!!!!! as of now. Im going 849cc on this build.

Im also running an X2 nozzle. I guess Ill be leaving my pump where it is... I cut the bottom of my hull tonight, right through the rear mounts. How did you get the bulkhead cut out? and the tray area? Im kinda stuck here now with the bottom cut up. that and removing old turf from my revs and tray.

lol, Grinder out. Cut less than you need then go back and cut to fit once it out and you have room to work.

 

[Cannibal]

Another question. Why not go with a yamaha powerplant? A 61x cyl/62t bottom 701 would give that small hull alot of snap. Its not too much trouble to put one in a js.

I have 2 SN hulls sitting here, one will get a top deck conversion and all the Yamaha power plant items I have. I have a running X2 that got the 750 and other items from a 750sx and that hull is still sitting here. So that's why mine will go Kawi power. However, if I had 2 complete drive trains from Yamaha, the second hull I have would get grafted in instead of the 750sx hull.

Im also running an X2 nozzle. I guess Ill be leaving my pump where it is... I cut the bottom of my hull tonight, right through the rear mounts. How did you get the bulkhead cut out? and the tray area? Im kinda stuck here now with the bottom cut up. that and removing old turf from my revs and tray.

Ya, I"m dreading the bulkhead area as well.

 

[Cannibal]

Its how I saw things. Cut that shaft. To have room to run any pipe you have to get the motor back. I want the weight centered. I am thinking of cutting a inch or to off the back atm. After thinking and reading the post, it would be easier if ur really want to set back the pump farther. The bulk heads line up the way Im doing it, makes easy to glass back.

Yep, the bulkheads lined up the way I measured too

 

[driftmaster]

Lenzi's ski looks to be five foot from back of the ride to where the rocker starts. Going by his arms and the grip in the pic.
I don't care how this or really any ski handles above 25 mph. Remember what were trying to do whit them.

The bulk head is not that bad. $30 grinder and a dremel and it will come out.

 

[driftmaster]

Yep, the bulkheads lined up the way I measured too

Not right on but very very close. That is if you take the back ride plate mounts to the back of the ski.

 

[tnj4life]

Kawi parts are CHEAP!!!!!!!! as of now. Im going 849cc on this build.

Shawn you should have spent more time pickin up those aluminum cans so you could buy a yamaha powerplant. hehe. Actually id like to see how a well built 750 performs, mine wasnt worth much.

 

[Brian_216]

So I did some measuring. My X2 trim from flange that bolts to the pump to the end of the nozzle measures 10". Cutting the hull flush with the back ride plate mount leaves the nozzle protruding 4". If you mount that even with the back of the bond line on the 300, you still have 4" hanging out the back. If you left the 750 bottom in one piece until in front of the motor mounts, you end up close to the fuel tank, but it would work for some exhausts. I was hoping to use my 750 limited pipe, and it doesn't leave enough room in front of the engine for that. So, I'd have to move back my engine another 2", which means it will make 6" of nozzle protruding past the ski. I mocked it up and there is just no way 6" protruding is good. Looks like a PITA to even get on the ski.

So, I'll probably be mounting mine like above, where the back hole of the ride plate mount is even with the back of the existing 300 hull, not the bond line. The nozzle will stick out 4" past the hull, but only 3" past the bond line (hull to bond line is only 1") and I'll have to use custom engine mounts that move the engine toward the pump by 3", giving me the same 2" I was looking for above (because I'm setting the pump 1" forward than the above measurements).

If anyone is using a regular 750 nozzle, they are only 7.5" not 10". So more can be done with them.

why not cut your driveshaft and re thread it? Then you can set the motor back as far as you like and leave the pump where it is? 4" out isn't horrible.

 

[Cannibal]

I was hoping to leave the bottom hull of the 750 complete for simplicity sake and strength. It would be nice to leave the motor mounts and pump one piece so there would be one less joint to potentially fail and less to have to measure and align.

 

[Brian_216]

tomorrow I start sanding. my plan is to use small metal plates on the outsude of the hull and screws to hold it where I want it. Tape over the seams and glass from the inside first. After thats dry Ill glass the bottom of the hull after removing the plates and screws. I have 1/8" gaps in spots, I didnt cut very nice. Where are you guys getting flotation foam from? I was thinking of using great stuff but heard its no good.

 

[Cannibal]

Pink polystyrene from HD or Lowe's. Get as much in there as possible. This means cutting little pieces to fill in gaps. IMHO, it's the only way to foam a ski. You can also fill gaps with Great Stuff to lock it all together.

I will be installing Versi-plugs or those SeaSense plugs as well to keep the area under the tray dry as possible. There is just no way to keep out 100% of the water.

 

[driftmaster]

Shawn you should have spent more time pickin up those aluminum cans so you could buy a yamaha powerplant. hehe.

Real funny Trent, .


Tonites work.

 

[tnj4life]

Great stuff is great for houses, not so great for skis. Too many voids left inside of the foam once expanded and too you cant pour it in like 2 part.

Go to bed shawn.I believe you helped that ugly 300sx nose, looks good.

 

[driftmaster]

I have one more pour.

 

[McDog]

All nighter huh? More power to you.

 

[Brian_216]

Im flattening out the point on the bottom when I shape the nose on mine. the bottom of my 750sx was mostly flat coming up to the nose. Yours is looking good- nice work man.