Hello to all,
I will try to make this brief but inclusive. I have purchased, but don't have possesion of a 27 foot 1990 Carver with twin 6 cyl 431 duoprops. The outdrives have the digital trim gages. During the sea trial, the starboard trim fucntioned normally at slow speeds. On plane, at cruising speed, the starboard trim would go to -8 (pushed up tight against the transom). While cruising, you could use the control to bring it back to zero, but it would drift back down to -8 within 10 seconds. I told the broker I would not purchase the boat. The current owner paid $1000 to have the pump replaced and I went on the 2nd sea trial. during the 2nd sea trial, the trim fucntioned normally at slow speeds. At cruising speeds, the drive remained in position without drifting down on its own, but if the control was used to lower the drive, the drive would respond to downward movement, but would not come back up to zero unless the boat speed was reduced to idle. The new pump was also very noisy. The broker says the trim cylinders need to be repalced at a cost of $1500. I agreed to a reduced price and have purchased the boat.
Now...
My thoughts, based on my limited knowlege of hydraulics, if the o-ring seal was bad in the cylinders, the drive would drift down under the weight and foward torque of the props, correct? The drive does maintain it's position under power. I think maybe the new pump is not generating the proper PSI to raise the drive under power. Air in the line? Is there a vent screw or do you just cycle the trim/tilt to remove air?
I will try to make this brief but inclusive. I have purchased, but don't have possesion of a 27 foot 1990 Carver with twin 6 cyl 431 duoprops. The outdrives have the digital trim gages. During the sea trial, the starboard trim fucntioned normally at slow speeds. On plane, at cruising speed, the starboard trim would go to -8 (pushed up tight against the transom). While cruising, you could use the control to bring it back to zero, but it would drift back down to -8 within 10 seconds. I told the broker I would not purchase the boat. The current owner paid $1000 to have the pump replaced and I went on the 2nd sea trial. during the 2nd sea trial, the trim fucntioned normally at slow speeds. At cruising speeds, the drive remained in position without drifting down on its own, but if the control was used to lower the drive, the drive would respond to downward movement, but would not come back up to zero unless the boat speed was reduced to idle. The new pump was also very noisy. The broker says the trim cylinders need to be repalced at a cost of $1500. I agreed to a reduced price and have purchased the boat.
Now...
My thoughts, based on my limited knowlege of hydraulics, if the o-ring seal was bad in the cylinders, the drive would drift down under the weight and foward torque of the props, correct? The drive does maintain it's position under power. I think maybe the new pump is not generating the proper PSI to raise the drive under power. Air in the line? Is there a vent screw or do you just cycle the trim/tilt to remove air?