Anyone have any idea about how long an engine should last? I treat mine really well and put all the after run oil and stuff in it. I do my job to see that it stays clean of dirt, but I have never really opened it up (don't trust myself) other then taking off the heat sync and the piece that holds the glowplug in place (something called a button) to clean out the heatsync out really well. Is there anything else that I should do to take care of the engine, and how long should they last?? Do they usually last a while? Do they need parts often??