Today I changed the oil and replaced the oil filter cartridge. Tomorrow I will change the final gear oil and differential gear oil, as well as clean the air filter.. Now understand I am a first timer at all of this maintenance stuff. From the service manual I can see where to put the differential gear oil in but not the final gear oil. Its says put it in the final gear case, what the **** is that and where is the opening to put the oil in? Also, I don't think I could check the valves because I don't have a feeler gauge or a tappet adjusting tool right? Should I have a Yamaha dealer do it or could the Polaris shop right by my house do it? The owner's and service manual say to clean the air filter every 20-40 hours. How often do you guys do it? Am I leaving out anything major any of you would suggest doing, thanks for the input, Ben.