90 hp just rebuilt

[jeremy5780]

i just rebuilt a 1998 90 hp cross flow put in the test drum and fired it up. Motor runs good other than it idles high i dont have a tach hooked up so i cant give exact rpms but from experince i can tell it is idling high i tried adjusting all the idle screws ect with no luck i can back the cam and follwer off so they are not touching the throttle valve and all the flaps inside the carbs are fully closed and with nothing touching the throttle valve it still idles high. If i try to puch on the throttle valve to close the carbs it does nothing but if i open them it revs up with no hesitation I have not tried to mess with the timing nor have i taken the carbs apart to check the float. Any ideas?

 

[jeremy5780]

Re: 90 hp just rebuilt

no suggestions where to start?

 

[Dhadley]

Re: 90 hp just rebuilt

On your motor the idle rpm is set by the timing advance with the carbs completely closed. You need to make sure both carbs have the butterflies completely shut. Then to set the idle lower you'll move the timer base back (reduce timing).

The motor will idle higher out of the water (little / no backpressure). It'll probably be around 1000 or so out of the water. In the water it should be around 650-700 in geat. Probably about 850 or so in neutral.

 

[jeremy5780]

Re: 90 hp just rebuilt

I just checked it and the timer base is already as far back as it will go!!!

 

[jeremy5780]

Re: 90 hp just rebuilt

any ideas dhadley?

 

[Dhadley]

Re: 90 hp just rebuilt

Remember it'll idle higher out of the water. Have you loosened all the linkage screws on the starboard side of the carbs? Ones on the carb and the one between the links?

 

[reeldutch]

Re: 90 hp just rebuilt

dont guess hook op a tach .