I have a 2-stroke Mercury 5 horse engine. To start it at the beginning of the season and to run the gas out at the end of the season I fill up a garbage can with water and run it. I notice oil in the water eventually. Can prolonged running of the engine in that water (with oil in it) cause problems?

I'm guessing you empty it each time you are finished or you are going to end up with some pretty nasty water.  That oil you see is why the national park service has banned two stroke engines and a lot of small lakes won't let you use them. 

As for hurting the engine, won't bother it.  Probably just gives it a little oil it would never see otherwise.

Is there a NPS ban on Two-Strokes? I have read it was only certain older motors on a handful of lakes out west.

Edited:
The two stroke ban by the NPS is only for non-carbourated PWC inboard engines, not bass boats:

https://www.nps.gov/lake/learn/management/twostroke.htm

 

 

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Does this rule apply to all boats?

Presently, the two-stroke engine ban only applies to personal watercraft (Jet-Skis, SeaDoos, WaveRunners, etc).

 

 

 

Thanks for the info

 

I haven't followed up from their initial plans for the two stroke band.  I know BRP and Mercury were fighting them hard because their DFI motors were well within the EPA guidelines.   The tree huggers had them Initially banning all two strokes on land and water. 

There are still a bunch of lakes that don't allow them, and most water sheds don't allow them