do it up. I pressure wash both my sleds inside and out, and I hit my truck motor about every 3 times I go to the car wash with the pressure washer also. I used to keep a carb cap and take my air cleaner off and all that nonsense, and just quit doing it. they are made to keep out some moisture, just dont be senseless and spray right into the air cleaner. on a sled just block the intake of the air box. I would be more worried about washing it running than not...