hello, i have a unique problem. my boat with a 250 overheats only at idle. i have changed the impellar, thermostats, and bypass valve (which was bad) the motor seemed fine until the bypass valve was changed. now it overheats below 1000 rpm. if the motor is bumped up to 1400, overheat alarm goes off. this is weird because you can idle 5-6 minutes before alarm goes off. when alarm sounds, i felt the water from the teltale hole, and it is barely warm.
any help would be great!
i did notice something else. the water coming out of the tetale hole at idle is not very strong. i have noticed that when i get in the 1400 rpm range (and above) water, by massive amounts now comes out of the rear exhaust port. i guess i dont know what condition (rpm or temp) makes water come out of the rear exhaust hole. it may be that the water pump cannot overcome the newly installed popet valve on the bypass?
any help would be great!
i did notice something else. the water coming out of the tetale hole at idle is not very strong. i have noticed that when i get in the 1400 rpm range (and above) water, by massive amounts now comes out of the rear exhaust port. i guess i dont know what condition (rpm or temp) makes water come out of the rear exhaust hole. it may be that the water pump cannot overcome the newly installed popet valve on the bypass?