loss of power on take off

[thumbtuckr]

i have a 93 xi 750 when trying to pull a skier or tube i lose power at take off the ski runs fine when just riding but still boggs some when giving it full throttle on take off is the carb needing ajustment thanks for the help tim in ks

[Dan DePardo]

Hi Tim;
Is the boat completely "stock"?
When was the last time you put a new set of plugs in it?

You probably have a mild carb tuning problem, but you'll need to determine which of the two typical low speed carb symptoms you have...if you're low speed mixture is lean, when you snap open the throttle from idle the boat will stumble, and possibly stall. If your low speed mixture is too rich, when you snap open the throttle, acceleration will be poor, but the engine will eventually "clear out" and run well at most throttle settings.

My guess is that your low speed mixture, combined with the typically high OEM pop-off pressure, is a little too lean, especially if you're riding right now in springtime air and water temps.

Try tweaking the bottom screws (idle mixture) on your carbs 1/8-1/4 turn open (counter-clockwise).
Temporarily pull off the plastic "limiter" caps if they're still on the screws, then replace the caps once you have things properly adjusted.
Make note of how much you adjusted the screws, just in case you need to go back to the original setting once summertime temperatures arrive.

Since the boat is nearly 10- years old, I also recommend cleaning and rebuilding those Keihin carbs sometime soon. If you have a worn throttle shaft (vacuum leak), or a leaking needle and seat assembly, you'll never be able to get the boat tuned right until you replace the ungood parts.

Dan

[Bryan Glynn]

I'd also take a compression reading and make sure it's in the ballpark.