Okay here we go.
1.The small hole in the cover does indeed have a hose which connects to the underside of your spark arrestor(air filter in auto terms).Never operate the boat with arrestor not in place.It's mandatory to run your blower(if so equipped and it should be)for about 5 to 10 minutes before starting your engine).To be sure you can also open engine cover as well.The reason for this is that if you have a fuel leak the fumes will collect in the bilge area of the boat and the smallest spark will make you go boom.That being said it's always a good idea to inspect your fuel lines for damage.While on the subject, if you ever need to replace the starter NEVER replace it with an automotive unit.The marine starters also have built in spark arrestors.
2.The reservoir I believe is for your trim pump which of course the level will change depending on the position of the gearcase.I think this boat is too old to have a gearcase reservoir but I'm not 100% sure.
3.Like 05 woody said this is a raw water cooling system.There is a water pump on the engine and also a water pump(impeller) in the outdrive.Depending on usage,salt water or fresh,the impeller should be changed every season for salt and you may be able to get away with every two seasons for fresh.Gearcase oil should be changed every season as well. That also means when the weather starts to get colder the engine must be properly drained and winterized.Hope this helps.Charlie
