750sxi high speed stall

[pescado23]

I have a 750sxi twin carb stand up. It seems to stall at high speed. It kills the engine if I open up the throttle past 1/2 throttle. I rebuilt the carbs and set them up to the stock setting. turned them rich for the upgraded intake air filters. it seems to me that maybe the reed valves are worn out. it acts like it has an over rich condition. I tired to lean it out with the screws but still no luck. it has enough juice to move at about 3/4 throttle when set at 1/4 throttle. I checked the movment of the butterfly it moves like the throttle should. Is there any thing I should be checking as well as the reeds? the reason I rebuilt the carbs was the rear high speed screw fell out of the seat vibrated out of the carb check the seats looks good and to specs. thanks for the help in the past and the future.

Pescado

[SXRider]

Re: 750sxi high speed stall

I would take the carbs apart again to check if it's put back together correctly. Sounds like fuel starvation at full throttle that the internal fuel pump is not working correctly. Maybe the check valve is no good or the diafram is bad or maybe the pulse line is leaking. With a set of Aftermarket F/A, you need to either rejet or lower your pop off pressure to compensate the increase air flow. But that you will feel hesitation only at 0 to 1/2 throttle. Good luck.

[Nisse Järnet]

Re: 750sxi high speed stall

I have a 750sxi twin carb stand up. It seems to stall at high speed. It kills the engine if I open up the throttle past 1/2 throttle. I rebuilt the carbs and set them up to the stock setting. turned them rich for the upgraded intake air filters. it seems to me that maybe the reed valves are worn out. it acts like it has an over rich condition. I tired to lean it out with the screws but still no luck.

Pescado

My -90 Super Jet acts just like this!! I have a new igition coil, and two new 46mm mikuni. But it runs like it did with the old 44:s and old ignition coil =( The engine has 701 cylinders and a kawasaki 750 intake welded onto the crank. It ran very good before the problems started! I now suspect the reeds (boysen) It runs nearly perfekt directly after warm up but then it starts to go worse and worse all the time. its just like its over rich. at around ½ thottel it runs pretty fine. Is this a reed valve problem??

[Nisse Järnet]

Re: 750sxi high speed stall

Help!! This is starting to get very annoying :(