A little bit of history.
About three months ago I bought a 268DA Sea ray Sundancer with the 7.4L Mercruiser engine.
Almost immediately I had drive problems. Second time out I felt a 'clunk' and I assumed we hit something but it was deep and middle of the channel. After the 'clunk' the prop appeared 'spun' and we limped into the marina.
I pulled the prop and the hub was pretty old and worn and appeared spun. Put new hub kit in and went back out. Under load the boat would not plane. The WOT RPM's maxed out at 3800rpm (should be 4500rpm). While plowing through trying to get on plane with 6 people we felt another 'clunk' this time way out in the navigation lane so I'm pretty sure we didn't hit anything. But, again, there was damage to the prop hub and, this time, we needed a tow.
Back at the marina we noted that the prop was a SS 15.25x19" which was WAY OVER pitch for this boat. OEM prop should be a 15.25x15.
I told the mechanic to tear down the outdrive. He found a twisted driveshaft and enough metal shavings in the oil to make it look like metallic paint.
At this point I ordered a new sterndrive with a 1:47 gear ratio (original OEM 1:32 but not available anymore).
Got boat back yesterday and repropped with a 16"x16" to take in account the new gear ratio.
Did a run for two hours at very low rpms (800-1500rpm) to break in new outdrive.
After two hours I did a run up to 2400rpms on calm flat water and felt the engine 'let go'. No clunk or other associated noise. The engine just felt like it disengaged spontaneously.
I immediately pulled back the throttle to neutral and opened the engine compartment to see if I could smell burning rubber (coupler?). I smelled nothing. I reengaged the engine and idled back to the dock. I did not try to add any more power for fear of damaging anything. Going slow it worked flawlessly.
To me it felt like something just 'let go' like maybe the engine coupler? Maybe that's part of the original problem? The old yoke shaft looks good and doesn't have any melted rubber on it. It also came across like cavitation or ventilation but the drive was tucked down and trim was close to neutral I believe.
The outdrive does have a drive shower hooked into a bolted on Whale-Tail. Would the Whale Tail influence anything?
My question is where do I go from here? What can I check or have the mechanic check short of pulling the drive back off? I am taking her out again tomorrow to see if the problem repeats.
Thanks for any insight someone may have.
About three months ago I bought a 268DA Sea ray Sundancer with the 7.4L Mercruiser engine.
Almost immediately I had drive problems. Second time out I felt a 'clunk' and I assumed we hit something but it was deep and middle of the channel. After the 'clunk' the prop appeared 'spun' and we limped into the marina.
I pulled the prop and the hub was pretty old and worn and appeared spun. Put new hub kit in and went back out. Under load the boat would not plane. The WOT RPM's maxed out at 3800rpm (should be 4500rpm). While plowing through trying to get on plane with 6 people we felt another 'clunk' this time way out in the navigation lane so I'm pretty sure we didn't hit anything. But, again, there was damage to the prop hub and, this time, we needed a tow.
Back at the marina we noted that the prop was a SS 15.25x19" which was WAY OVER pitch for this boat. OEM prop should be a 15.25x15.
I told the mechanic to tear down the outdrive. He found a twisted driveshaft and enough metal shavings in the oil to make it look like metallic paint.
At this point I ordered a new sterndrive with a 1:47 gear ratio (original OEM 1:32 but not available anymore).
Got boat back yesterday and repropped with a 16"x16" to take in account the new gear ratio.
Did a run for two hours at very low rpms (800-1500rpm) to break in new outdrive.
After two hours I did a run up to 2400rpms on calm flat water and felt the engine 'let go'. No clunk or other associated noise. The engine just felt like it disengaged spontaneously.
I immediately pulled back the throttle to neutral and opened the engine compartment to see if I could smell burning rubber (coupler?). I smelled nothing. I reengaged the engine and idled back to the dock. I did not try to add any more power for fear of damaging anything. Going slow it worked flawlessly.
To me it felt like something just 'let go' like maybe the engine coupler? Maybe that's part of the original problem? The old yoke shaft looks good and doesn't have any melted rubber on it. It also came across like cavitation or ventilation but the drive was tucked down and trim was close to neutral I believe.
The outdrive does have a drive shower hooked into a bolted on Whale-Tail. Would the Whale Tail influence anything?
My question is where do I go from here? What can I check or have the mechanic check short of pulling the drive back off? I am taking her out again tomorrow to see if the problem repeats.
Thanks for any insight someone may have.
