300/440/550 sbn44 settings

[skipro61]

I just bought a new sbn44 for my modified 1990 550sx..It came with the following settings..120 L 140 H 2.5 needle 80g spring...Does anyone know a better starting point before I get started?

 

[N2 H2O]

What mods do you have? I"m running 105 low, 125 high, 2.0 n/s, 80g spring. My ski has a milled head, coffmans halfpipe, prok f/a, and a jetworks flow control valve.

 

[skipro61]

It has a milled head,bored all the way,Factory halfpipe and waterbox,prok f/a,impeller...The bn44 I was running seem to work fine above bottom end.No quick throttle response..I also got the BCW racing intake to go with carb.

 

[N2 H2O]

I would start with the settings I listed. Our motor setups are virtually the same


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[skipro61]

Ok thanks I will.

 

[skipro61]

My next question is how to get rid of rev limiter on my 90 550sx now that I have the sbn carb.

 

[N2 H2O]

My next question is how to get rid of rev limiter on my 90 550sx now that I have the sbn carb.

Cut the wires to the ebox, disconnect it from the fuel lines, and take it out. You will need new fuel line to run a new line from the carb to the gas tank or a double sided hose barb to connect the fuel lines where the rev limiter was.


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[skipro61]

Got it thanks!

 

[skipro61]

I appreciate your help and have another question..Where to hook up lines to new sbn 44 carb..There is the one on the fuel pump on the left and the ones on the right,top and bottom...I know where the primer goes lol....

 

[N2 H2O]

The pulse line from the crankcase goes to the fitting on the fuel pump. The in line goes to the bottom fitting and the return goes to the top fitting.


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[N2 H2O]

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[skipro61]

Thats great thanks for the pic.I'm redoing my lines and getting rid of the on pick-up and going to just use the reserve.Kinda lost track of one of the lines.Where does the return line from the carb hook up too?

 

[N2 H2O]

The return fitting on the gas tank.


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[skipro61]

Thanks for walking me through this,it started right up.Awesome!

 

[cookn]

nice moves on the sbn, yea i didnt have much luck with the 2.5 N/S. im running the stock superjet jetting on my 550 and it works awsome as well with a full mod motor. its 1.5N/S and 65 gram spring 135 main 113.5 pilot