951 in my 750sx freestyle buildup

Billybo455

Billybo455

Location
Central FL
low side jetting, they are mikuni carbs right? the screws lowest on the carbs are the low speed jetting. i'd screw them all the way in and see where you're at. then back them out to where they were -an 1/8 a turn. but if you don't know how to set carbs up. ask a buddy that can. :)
 
Brian_216

Brian_216

Location
Harveys Lake PA
buckshot BRM 50s there are 2 screws on top one close to the filter and one closer to the motor. I was told the one closest to the motor is the low. Also the suggestion I got was take the 80 jet out of the return side of the rail and go bigger, 80 to 130 they can run at. Another cool trick I hear about was the anti siphon valve inside can be doubled up also checked to make sure its sealing.
 
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Brian_216

Brian_216

Location
Harveys Lake PA
I hope to have video this week, this thing rips now that I got the jetting sorted out. It was working fine with the new jetting until a spigot mount failed on me.

I changed the jets to a 150 main, 115 pilot and a 100 on the return end of the fuel rail. It felt well within reason like that and nothing some fine tuning wouldnt be able to fix.

I am so happy with this build. After all this time to finally have it running and put a smile on my face when it nearly dislocates my shoulders with an amazing hole shot. I will admit, its heavy. The rub rail sits almost below the water line up front when its just floating in the water. I dont see me doing any tricks on it, other than jumping wakes with all this added power. I may just end up selling it and build a stroker superjet in the next year or 2. but its going to be fun to ride this summer.
 
Brian_216

Brian_216

Location
Harveys Lake PA
eastbay said:
^^^ thats what i did!!! ripped it my sxr951 for a year than parted it out! have fun on it!
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What did you build next?

Im not sure if parting out would be a good option for me, since the pipe was cut way short to fit the sx hull. Id rather sell the whole thing once its perfect and painted/returfed- or trade for a nicely modded RN, or something with an aftermarket hull, 66e conversion etc. Id love to have something capable of a flatwater backflip.
 
Brian_216

Brian_216

Location
Harveys Lake PA
Worst day of my life... Water got in the mag cylinder early on leaking past the head. The reason I was getting a very wet plug up front and was absolutely stumped with the jetting. well enough water in there washed it out and did some damage. A new top end is going in this week and new o rings are coming for the Rossier head. (this was no fault of the rossier head, I did not have o rings when I got it 2nd hand and tried to use a headgasket to get it to seal- expensive lesson)
28auvjc.jpg

Lead to this
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tore the cases apart and cleaned the crank bearings, re lubed and re sealed

then lots of this...BEER makes everything better!
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I am seriously bummed, but at the same time relieved now that I know why the back plug was chocolate and perfect and the front wasnt burning. I was really irritated with the jetting and ready to buy NOVIS
 
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SNOWMAN

SNOWMAN

HE HATE ME
Location
LAKELAND CUZ.
how fast was it before you blew it up? jk. that sucks bro. you think it was doin 70mph+? there are some 951 builds on youtube and they look fast, i dont know about 70mph fast....what do think your biuld was capable of?
thankz
 
Brian_216

Brian_216

Location
Harveys Lake PA
I should have updated this sooner.. I got it all back from the machine shop bored .5mm over, sold the buckshots and have a set of novi 48s on the way for tuesday. Still need 1.5" tall filters and im ready to go again.

Speed? well I bought a prop from a user on the other forum who had it in a kawidoo with a stock pump and it ran 59 mph. I didnt get to GPS it the 2 days I had it running at the lake but Im going to say on its best run it was doing every bit of 50. I fell off at that speed and tumbled 2 full turns on top of the water so yea, Im going to say its pretty fast.

Not a freestyle boat by any means. Im thinking of parting it out this winter and building a 300sx with a 66E for next summer. Id really like to sell the whole thing when the season is over but I doubt there will be any interest in a 951 SX?
 
the WaTeRhAwK

the WaTeRhAwK

fryin' up a/m electrics..
Location
okc
Brian_216 said:
I should have updated this sooner.. I got it all back from the machine shop bored .5mm over, sold the buckshots and have a set of novi 48s on the way for tuesday. Still need 1.5" tall filters and im ready to go again.

Speed? well I bought a prop from a user on the other forum who had it in a kawidoo with a stock pump and it ran 59 mph. I didnt get to GPS it the 2 days I had it running at the lake but Im going to say on its best run it was doing every bit of 50. I fell off at that speed and tumbled 2 full turns on top of the water so yea, Im going to say its pretty fast.

Not a freestyle boat by any means. Im thinking of parting it out this winter and building a 300sx with a 66E for next summer. Id really like to sell the whole thing when the season is over but I doubt there will be any interest in a 951 SX?
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you need to put a lower pitched prop in it to increase the low end and knock off the top speed. if you're getting 59 mph out of it, the pump is loading up too quick for the engine to hit the are of the powerband that will jump it out of the water.
 
Brian_216

Brian_216

Location
Harveys Lake PA
I had it out of the pump the other day, it is a 15/20 solas. Dont get me wrong the low end hit is amazing, It almost dislocated 2 shoulders! one time when I hit the gas the grips got out of my hands and I was dumped off the back. it hits very hard, just weighs an estimated 400 lbs. a backflip gone wrong would hurt like hell to be under it. I want a new project- smaller and lighter, same power.
 
the WaTeRhAwK

the WaTeRhAwK

fryin' up a/m electrics..
Location
okc
Brian_216 said:
I had it out of the pump the other day, it is a 15/20 solas. Dont get me wrong the low end hit is amazing, It almost dislocated 2 shoulders! one time when I hit the gas the grips got out of my hands and I was dumped off the back. it hits very hard, just weighs an estimated 400 lbs. a backflip gone wrong would hurt like hell to be under it. I want a new project- smaller and lighter, same power.
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just saying, it being a powervalve setup, it will probably hit a lot harder off the bottom than it already does if you bring the prop down. If it's hitting as hard as you say it does already, and you're getting almost 60 mph out of it on the top, that should be an amazing freestyle setup with the right prop. like a 13/18 or 12/17, something like that.
 
Brian_216

Brian_216

Location
Harveys Lake PA
yea, I noticed that riding today, I can really feel it hit once its almost at its top speed.

well if you see anything you like the complete motor, carbs, pipe and electrics are being parted out as soon as the water gets cold up here. Im building up a 300sx for next year and want to go all out on that with a Yamaha motor. I would love to sell this thing complete, drop in and go, custom shortened wiring harness for a kawidoo, pipe will fit a 750sx hull and it will fall into place on the stock rear 750 motor mounts. I still want to put a few more tanks of gas through it before I say goodbye. This thing is fast, very fast. just not a freestyle motor or weight class.
 
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