Having taught small engine repair and rebuilding, here are a few tips to help you out.
1. Decide for sure what you want to do if your engine is beyond rebuilding. I’ve had people pull an engine apart and then decide they don’t want to rebuild. You now have an engine that will cost you to put back together or you are now either going to junk everything, engine and unit.
2. Set a dollar limit you want to spend. Before ordering any parts, have a complete list of what you need and check it four times.
3. Go through every part and measure everything at least twice. More than once I’ve seen people miss measure or forget to measure parts and find out they need to spend more money because something is not in specs.
4. Don’t, I repeat DON’T set a time limit if this is your first attempt. Will only cause a nightmare down the road.
5. Find out if you have a good machinist in your area who can cut cranks, bore or hone cylinders and do valve work. Need to know what expenses you may run into.
6. If you decide you really want to rebuild, check to see if a short block is available and cheaper than you doing all the work.
7. Don’t rely on your own knowledge, come back and ask questions. We are here for a reason.
8. Personally I would get any parts needed from a local dealer. If you order from him you have a valuable resource if help is needed down the road.
9. This manual will help you out.
https://drive.google.com/file/d/0B6NaqjIxWV1ybEN0LWo3azl6OUU/view