Re: engine oil
the recommended oil for 4-stroke outboards will have a rating of "FC-W". Although regular auto 10W40 oil will work, it's recommended to use an FCW oil instead. One problem that 4str outboards have is that they don't run hot enough. This causes gas to get by the pistons and go into the oil (so called, 'making oil' in the industry). You'll notice this when you check your oil and it may smell of gas (and the oil level is abnormally high). The gas ends up diluting the oil and reducing the viscosity of the oil. The FCW oil has additives to help reduce the dilution effect. It doesn't eliminate the problem, but it does help in keeping the viscosity of the oil at a normal level.
The only real solution is to try and reduce the amount of time trolling around at slow speeds (ie: running higher speeds builds up the engine temp which makes the piston rings expand more and thus keeping gas from getting by the rings). And of course, change your oil on a more frequent basis....using FCW rated oil
For a couple of bucks more it's well worth the investment. I always find it interesting that people will spend $10K on an outboard and then don't want to spend an extra few dollars a couple of times a year to use a high quality oil; the lifeblood of the motor.
