9.9 Evinrude 4 stroke running rough question??

[MikeMo]

I run an Evinrude 9.9 4 stroke as a kicker (model E10R4EEB). Last time out it started fine, trolled at 2.6 for awhile and then would speed up to over 3 mph. We were continually adjusting the speed as it would not maintain a constant speed. I recall having a similar problem before. Solved it , I thought, by running the engine at high rpm's for a bit.
I'm running it off of my main tank for my mercruiser.
I'm guessing that the carb etc. needs a good cleaning. Can I use sea foam to do this?? What procedure should I follow?
I have never taken apart a carburetor and am hesitant to do this. Is it necessary??
Thanks.
MikeM

[iwombat]

Add some seafoam to the fuel and run it through. Let it sit for a couple of days and run it some more. Both your motors will love it.

If that doesn't clear things up a bit, you'll need to do some more investigations.