SX/SXi/SXi Pro 750 sxi motor build

[ejl22boo]

Ok I am looking at building a motor for a sxi and i am wondering what is my best options?

from what i have read it seems like the sxi lower end is better than the sxr lower end. so i was thinking of taking a big pin lower end with sxr cylinders bored out? I want a somewhat freestyle ski, and i cant afford a superjet or a xscream motor so i am going to try and do what i can.

so is this the best setup or is there another path i should go down?

also if this is posted before i apologize.

 

[fastony]

SXI and SXR are almost identical except the SXR is 2mm bigger bore, You can bore your 750 cyl. to 82mm like the SXR is, than have it ported add compression and timing ( ignition ) and pipe and a lighten flywheel and it will be a major difference. You just need to decide how much you want to go depending on running pump gas or race gas. Then add carbs and start lighten up your ski and be ready to rip!

 

[ejl22boo]

see the thing is, i dont have a motor right now, so should i just look for a sxr motor, because the bottom ends are the same or is there a benefit to having the 750 bottom end with sxr cylinders

my plan was to take the 800 cylinders and bore them to get more from the motor.

 

[fastony]

If you find a SXR motor you can bore it bigger without going with bigger sleeves, I have a 849 kit in mine without changing sleeves, with the 750 motor 82.5 to 83. is as big as you can go without changing sleeves so yes the SXR would be better!

 

[turbo325is]

sxi and sxr have way diffrent port timing there is a 2 or 3 mm diffrence in the exhaust port and i think 1mm in transfer port