Sorry but I think you should just pay what it costs and get it fixed by someone that knows what they are doing.
You are now more than capable of checking the oil and keeping on top of that, so once you have it serviced and fixed it will be good to go for quite a while with just regular oil top ups.
I appreciate that you want to learn. I would actually welcome that you do that. If you google or youtube about how engines work I am sure that you will come up with hours and hours of reading and watching. You need to understand how it works before you can fix it. Otherwise you are flying blind. Learning takes time.
The issue you are having could be any number of things.
Sorry leo, but the post with the arrow and circle got me. The yellow is the back of the crankcase and the red is the muffler.
Yellow, yeah that gets hot, not being experienced you would not be able to tell too hot, from hot, from not hot enough. If the motor has been running for a few mins, too hot to hold your hand on is normal.
Red, thats the muffler/exhaust. Hot hot very hot, dont touch.
Cheers, Bob.
