Re: 2003 25 Hp Johnson Comments/oil mix?
If you have no personal knowledge of the motor, I would start by changing the impeller, if it has never been done, along with the lu oil. Most like to do the impellers about every 3 years. I would also invest in a Service manual, it will pay for itself a few times over. Inspect and 'read' the plugs, and you may want to consider adding a fuel additive such as Seafoam or BRP's Carbon Guard. May also want to consider compression testing it, Im sure there are no issues, but is good to have a benchmark for future testing. Good luck.
