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If your concerned about moisture collecting in your engine during a prolonged non use, you might consider building a simple dryer, consisting of some silica gel beads, a plastic bottle, a fish tank air pump, some tubing, cork and a timer. Put them all together and you have one easy and cheap system that has worked very well for me.
I have the timer set for one hour run time per day. Adjust yours for your conditions. Once the gel is full of moisture, (Blue balls turn pink) simply pour them into a large pan and put it in the oven at 250 degrees until the balls turn blue again. This can be done over and over again. How often you have to do this is determined on run time and how much moisture you have in your area. For me about once every 2-3 months.
In the tennis ball tube, I have a cloth sack full of silica gel beads. Trim the metal ring off the tube, and it stick right into the exhaust pipe. Nice tight fit.
This is a open system, you can make it a closed system by having the intake of the pump suck air from the exhaust port tube coming from the engine. For me, this wasn't worth the extra work. This system has been in use for three years now. I purchased the silica gel online, just find the best deal. Tubing and cork from hardware store. Pump from Walmart. Timer I had laying around from Christmas Lights. In all it was less than $50 bucks.
If you have any questions, you can contact me at email@example.com