Ski wont plane out

[gldnrober]

Need help here.

SLT780 new engines, carbs rebuilt. had them in the shop several times this year and the problem still exists. with one rider I can get the ski to plane out but at WOT will only do about 36mph. and that is usually only after I goose the throttle a bunch of times or hit a wake lifting the ski out or a hard hit. with 2 people on board or pulling someone ski wont plane out and stays around 17mph. I am pre mix at 40:1. in any sharp turns no matter direction ski bogs down and wont shoot back out of the water. any help would be greatly appreciated.

[ph2ocraft]

How about a photo of the impeller/pump/liner area?
Have you checked impeller clearance?
What are your max RPM's while traveling 36MPH?

[gregbowler]

I had the exact same problem. This is what fixed mine:

Low speed screw 5/8 turn open
High speed screws mag 3/4 cen. 3/4 pto 1 turn open

[xlint89]

Did you have a new impeller installed?

[gldnrober]

New impellar and drive shaft was installed on one of them. Both Ski's are having the same problem. Dont recall what the RPM's are at WOT. if they went into limp mode (??) would that be the max they will go? both of them have had the oil injection removed but I dont think the dealer did anything with the sending unit. I am not sure how to tell if they are in limp mode.

[ph2ocraft]

You have a flashing lamp on the MFD?
Your max RPM's would tell a lot more.
The limp mode is set to roughly 4200 RPM.

[mystahagy]

...both of them have had the oil injection removed but I dont think the dealer did anything with the sending unit.

I'm new to this, but perhaps you're needing that 33-ohm resistor between the two wires that previously went to the oil tank?

[gldnrober]

Yes the lamp is flashing i believe because the fuel sending unit is out always shows empty. i will take them out again and see if I can find out RPM. I know on one of the ski's I cant move MFD off of MPH.

Thank you all again for all the assistance.

[xlint89]

If it shows low fuel (and the light blinking) you are in limp mode. Most likely the fuel float no longer floats. (gives a low fuel even though the tank is full) Also look into the oil sender unit. You can install the 33 ohm resistor, or just tie the fuel float into the full position. New fuel floats can be bought from Randy at Watcon.com (around $20) and in the mean time, you can open the elec. box and remove the grey wire from the board, this should bypass the limp mode. Be sure to reinstall it after you fix the issue, be it the fuel float or oil float.

[ph2ocraft]

What he said.^^^^^^^