This is a good one, but hang in there and let me explain. Looking at a 2003 Regal 4260 with twin TAMD 75, 550hrs. Owner has discounted the boat due to the unknown issue which happened in October and has not had it looked at yet. Boat is on the hard and winterized. Here is how he describes it.... A few weeks ago I took the boat out and the starboard EDC (Volvo’s electronic transmission control) started to act up. Boat ran up to almost on plane, then went into neutral. Turned around and went back in. Starboard forward was disengaged. I only had reverse. This may be anything from a loose connection to possible needing a trans overhaul. I am almost certain it’s something electronic. I’ve dropped the prices considerably to move the boat on. Took the boat out many times this summer. She ran great. Summer prior (2018) I had a very high powered stereo hooked up to my 2 starter batteries in my 2003 Regal 4260 Express. My port side would go dead and I'd only have starboard to dock the boat. No forward, no reverse. I discovered one of the 3 breakers in the control box mounted on the side of the engine would pop. I'd push it back in and the controls would start working again. Ultimately, I replaced the breaker and port side has run flawlessly. Fast forward to summer of 2019. Startboard side starts acting up. Nothing at all in forward. Reverse was perfect. I suspect stereo hooked to engine batteries was interfering with EDC's. Pulled stereo off batteries, take her for a run, she runs perfectly. Summer of 2020; all is great until October when I take her for a run. She would pull hard until almost on plane, then just drop into neutral. Engine would rev, but no forward thrust. Reverse is perfect. Oil sample shows 358ppm for copper, 98ppm for aluminum, which Wix says is abnormal. Not severe which is their worst grade. I'm not sure if when the engine was pulling onto plane, then went into neutral and just revved, did it slip the clutch by possibly the solenoid being partially open and increased the level of copper? I'm trying to figure out if I have an electrical problem and or if the trans is in need of a rebuild. I swapped solenoid from forward to reverse on trans and nothing changed. Figured if seloniod was bad, I'h have no reverse with the swap. Thanks for anyones help! Thoughts on the issues? Engines run so I doubt its the EDC in its entirety. Not sure if I should pursue this boat or to run away. Price reflects the unknown issue which could be simple or could be expensive and a lengthy repair? Thanks as always.