200 ox66 1800 rpm limit

[joseph lamb]

Good afternoon,

I have a 2001 200 hp ox66 2-stroke , that has suddenly started to

limit its rpms to 1800 to 1900 rpm at WOT.

It does not stall , it just does not go .

Oil use is up , and fuel use is up .

Water pump is new and engine is running cool .

O2 sensor is clean , but it is original with hundreds of hours on it .

This motor has always run well since new .

If I operate the throttle control , from closed to WOT , three times quickly ,

the motor rpms go up and the boat planes out , but now top rpm is around

4500 , not 5400 like normal .

I do not know where to start on this one .

Thanks ,

Joe in Tampa , USCG Aux Coxswain

[jb123]

do you have digital gauges and does your alarm buzzer work ??

[joseph lamb]

No digital guages and the only time I ever heard the alarm sound was when I was flushing the motor and I did not have the hose turned up enough to flush the motor .
When I turn on the ignition key there is no alarm tone .
Is there supposed to be a tone ?? The oil tank warning lights all work well .
Thanks ,Joe

[99yam40]

Check compression, spark , and timing.
If all is well then monitor the fuel pressures/ vacuum to make sure that is good.
I believe You can disconnect kill switch lanyard and turn key to test alarm

[joseph lamb]

I will start as you suggest , with the basics at the beginning !

Still out of work and money is real tight now . I just use the boat for doing

USCGA patrols and they pay us nothing for maintenance , just fuel .

Thank you for all the direction >

Joe Lamb