I have a 2000 340 Sundancer with 7.4L Mercruiser Bravo 3. At the end of last season (Sept 2019) I began to experience an issue with my Port engine (only). Starboard is fine. I would get up to cruising rpm 3300, and cruise at the rpm for a while (15 - 30 mins), then suddenly, the Port engine would lose power and drop down to 1200 - 1800 rpm range. The engine would NOT stall, it would just lose power. Please note that the engine runs easily., smoothly and consistently in the 800 - 2600 rpm range with no issues at all. When the engine loses power, I would turn the engine off, then turn it on and the boat would be fine for several minutes, climbing back to 3300 rpm. Then the "issue" returned after several minutes. And Again and Again it occurs The Mechanics thought it's fuel starvation issue so they blew out the fuel line in Sept 2019 and this "fix" seemed to work for the remainder of the 2019 season. In 2020 season, I took the boat out for a few cruises and it seemed to run fine. Suddenly 2 weeks ago, this issue returned. Exactly the same issue as above. The mechanic blew out the fuel line again using a compressor on July 8. He bay tested the boat that same day and it ran fine for him. Today (7/14) is the first chance I had to bay test the boat myself and the issue returned when I tested the boat. Note: that once this loss of power issue occurs, the highest rpm I can subsequently get the boat up to is 2600 rpm, but no more than that. If I try to push it past 2600, it loses power I am stumped by this issue... Any ideas/suggestions/thoughts???? Is it Fuel???? Electrical??? Mechanical????? HELP???