What is the model number off the engine? It's probably stamped on the top of the cowling or at the side of the cowling.
There are many HM80's. Some have governor rods which run to throttle levers on the side of the cowling and others which run to a throttle arm on a platform above the carb.
Some engines have two rods. Others have one.
With the model number you can lookup the part number at the link below for the spring and probably get one at a local dealer. If not then online.
http://www.outdoordistributors.com/Tecumseh/Tecumsehpartslists.html
It seems you probably have two issues. 1. Setting up the governor rod and spring correctly. 2. A dirty carb that needs cleaning.
You might bring in your parts to a dealer. If he’s a helpful guy then he can probably tell you if you have the right parts by comparing to his stock. Bring in the engine number and look up the part numbers first.
After you have the right parts the spring location will be mostly obvious. For the rods their general location will also be obvious but exactly which hole will not be. For example the main governor arm usually will have 1 to three holes. The other end will probably have a few holes to connect into also.
If you post a model number someone may post a photo for you. I have a few HM80’s around. It’s not so critical though. You can set your governor by just hooking up the rods and spring and adjusting your governor “by the book”. There are several postings in the group archives on how to do that. It’s also available in the 3 to 11hp Technicians Handbook available on the net. Google that for a free download. I think Dennis recently posted the steps so search the forum on Dennis and within the last few weeks you should find it.