Bought this engine brand new in 2006 and have used it during the open water season, here in MA, each of those years, including this one. Spring of 2007 I installed a water separator (10 mc Yama filter). I usually disconnect the portable tank each winter and use the residual fuel in my snowblower. BUT, I have never run the carb dry when putting my boat in storage. This coming winter I was thinking about doing that, before fogging the cylinders. I would accomplish this using a barrel of water, which I use for testing the engine prior to launching each spring.
1) Is this a good/bad idea (drying up gas in the carb)?
2) Should I do something else, to clean the carb after running it dry? Especially since I've never done anything to date.
3) If I follow the same procedure as in previous years, will I loose HP due to gas gunk buildup in the carb, as time goes by?
4 Strokes don't depend on fuel for lubrication, so I don't see a hazard in running a single carb 4 stroke dry for storage. For really long term storage there might be some risk of drying out internal gaskets and seals, but I see that as an acceptable risk to avoid varnish.
4 Stroke carbs don't suffer nearly the varnish buildup that mixed fuel burning 2 strokes do. I never considered it a problem.
It is a good idea to always run Stabil or other fuel stabilizer in your gas.
Running the engine until dies will not get all the gas out of the carb. If you are going to run the gas out be sure to drain the carb or you will have gunk buildup in the carb. I don't recommend that you run the gas out. Put sta-bil in the gas tank and run the motor so that the sta-bil gas gets completely trough the engines fuel system. This will keep the carbs from tarnishing or guming up and remove any gunk buildup that may already be present. It will also keep all seals and gaskets moist so they don't dry rot, crack and leak.
Sta-bil will keep fresh fuel good for up to 24 months.
Yes, stabil will work fine with gas containing ethanol. In fact it is recomended that you use stabil with gas containing ethanol. Ethanol attracts water and the stabil prevents water from getting into fuel.
An even better product is SeaFoam which is available at the same places you buy Stabil. I won't delve into the scare tactics used by marina operators as it only makes my blood pressure rise. Treat the fuel, and go boating. Stabilize the fuel when finished for the season and put the boat to bed.