I finished up the cam shaft job on the Honda Rincon 680. The total time for the job was 11 hours and there was about $500 in parts.
I am always amazed at the amount of engineering that Honda puts into their machines. Just take a look at this photo of the oil drain plug. Could you have made a more complicated oil plug? Note that there is a aluminium crush washer and an o-ring on it. The service manual says that you are supposed to change both of them when you remove it!
Rather than spending all that time designing the worlds most complicated drain plug they should have figured out a better system for the oil filter. This photo shows a typical Honda oil change. The filter is a round paper element that goes in that hole in the side of the engine. When you pull the cover off the oil pours out all over the place and dribbles down onto the foot well. There is no way to change this filter without making a mess.
At least on this machine they have an element that is the same on both ends. On some of the Honda ATVs the filter element can mistakenly be put in upside down. If that happens it restricts all the oil flow to the engine. I have seen a few wrecked motors from this problem (I didn't put the filter in upside down, I just fixed the engines when someone else did).