SX/SXi/SXi Pro Pistons look ok?

I decided to pull off the head on my ski while going through it for the winter, ran fine before taking it apart but its been about 3 years since I rebuilt it. 750 bored to a 800, rec porting, stock rejetted carbs. ect, ect. Compression was 155/150 on a milled stock head. cross hatching is very light on the sides near the top of the cyl. Thinking about going to a AM head and 180ish comp.

 

tor*p*do

Squarenose FTW
Site Supporter
Location
NW NC
Piston crowns look good, maybe a little rich but that is OK
Cannot tell how the skirts are doing from that pic and without pulling the cases
 
Thanks for the input, I thought it looked a tad rich too but I'm not surprised, I never really got this dialed in and typically always kept it rich to play safe. A good tach will be used to get it dialed in for next season. I will pull the cyl off to inspect as well, I did crank seals the season before last but will check them anyway. Its cheaper to be too safe than repair later.
I was thinking ADA head for a sxr with 30cc domes, would that be right for my cylinder? Also thinking of going to v force 3 reeds, I currently have carbon tech ones on stock cages. I dont know if its worth the coin but I could always use more brap...
 

Mark44

Katie's Boss
Location
100% one place
Looks good IMO nice wash and I always go a tad rich.

Check your squish you may be able to just mill that head there is nothing wrong with it is there?
 
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Mark, there isnt any issues with it now but Tim at z force did tell me that the head had been milled before he did it and it was milled at a angle so he had to take a little more off. His target was 180psi when he did it but it came out to 155psi. I'm guessing the larger bore he did at the same time lowered the numbers a bit. Guess it was a waste to run 110 this summer lol. It did run better on it though. There is always the chance my matco gauge is off but I wouldnt think its off by 25psi. I'm going to pressure test the motor while its out and recheck comp with another gauge before deciding on a AM head or sticking with the stocker. Im trying to resist the temptation of pouring more money into this tank. If you and katie dont start riding more you might just have to sell me one of your boats :)
 
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