Have a 1987 DT-40C, Oil injection, No trim.
Motor starts & runs like a champ.
At idle & low RPM overheat warning sounds & excessive white smoke.
water flow at port looks ok.
Have changed thermostat & impeller looks good.

will run at high rpm all day with no problems.
I do not have any specialty tools so not sure what to check next?
Does anyone know the proper weight & brand of oil?