Huge thanks to Mike for pointers in fixing this. I always like to finish out threads and help the next poor soul that might encounters this.
So its fixed and it could be 1 of two things. The flame arrestor was FILTHY. So much so I could wipe the carbon off with my fingers at the side. Second, it could have been engine alignment. I could hear the starter motor struggling to move it by itself on first start.
First thing I did was service the outdrive. Impeller looked ok and changed it anyway with a new kit. New gear lube etc. Next up, did an engine tune up as it needed a service anyway.
- Spent about 6-7 hours aligning the engine using the precision alignment tool... as best I could - this would be done in a fraction of the time if I had a second person!!!
- Spark plugs - changed gap to spec
- Spark plug cables
- Distributor cap
- Oil filter
- Fuel filter
- Thermostat - old one was slightly rusted and corroded
- Full can of Power tune - the amount of carbon that fired out the back after the 15 minute wait was UNREAL!
Pleased to report its now like a rocket and my engine has been under performing this whole time.. I now get below the 4800 MAX WOT limit on the engine with the same prop. I was previously getting 4300 or 4400.
I hope this helps other people. Learned alot and thanks again to Mike (mmwjr)/this forum for all your help and support as always!