SX/SXi/SXi Pro 750SX Jetting?

B

balprix

Location
Long Island
I have a 93 750SX it has a small pin motor with 180 psi. Its all stock besides a dual Keihin 40 with 3 jets. Problem is it likes to run away. I did do a leak down and found a leak at the crankcase drain so I blocked that off. It's still running away. Ran it for about 15 seconds with my hands choking it, as soon as I take my hands off it runsaway. There is a bubble in the fuel line going from the rear carb to the front carb. I dont know if that would cause it but worth mentioning. I was thinking maybe my settings are wrong?

Pilot 45, Mid 72, Main 135
Low Screw 1 1/8
High Screw 3/4

Saturday im gonna pump the primer so fuel goes into a can so maybe I can get that bubble out and try again.
 
eeerieski

eeerieski

Location
NW PA
did you re-test for leaks after blocking off the drain?
Isn't it the general consensus that mikuni SBN carbs are the way to go? I have a single keihin carb on my 750sx that doesn't respond to adjustments well.
 
B

balprix

Location
Long Island
I did end up leak testing again, first time I had a leak at the schrader valve. This time I put a new schrader valve on my tester and there was no drop is pressure over 3 hour period. After that I took off the intake manifold to check the reeds, look good so I put new gaskets with silicone then I put new OEM carb gaskets (as opposed to my new WSM gaskets). Prime the carbs reel good, cranking with spark plug wires off and started it up and ran fine. I think the problem was in the :):):):) thin WSM carb gaskets I had.
 
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