A Year in Small Engine Repair Unit Study for Homeschoolers
The broken mower in your barn is a full year of high school credit.
A 36-week small engine repair elective for homeschool high school—with 13 hand-drawn labeling diagrams, 96 self-check questions, and every answer key you need to run it without knowing a carburetor from a camshaft.
The Gap
Somewhere around tenth grade, most homeschoolers hit the same wall.
Your student can write a decent essay and work through a chemistry unit, but maybe he can’t tell you why the mower quit in June. Neither can you. So it sat behind the shed until you paid someone eighty-five dollars to clean a carburetor, and you both agreed not to talk about it.
That is not a discipline problem or a character problem. It’s a curriculum gap, and it is the single hardest one to fill, because you can’t teach what you’ve never done.
Meanwhile, the trimmer won’t idle. The generator you bought for outages hasn’t been started since 2023. The chainsaw dulls faster every season and nobody knows why.
And every one of those is a lesson sitting in your yard, unclaimed.
The Shift
Here is what changes when you stop looking for someone to teach the class.
You don’t teach it. The engine does.
This guide gives your student the reading order, the vocabulary, the diagrams to label, the questions to answer, and the tasks to do — and it points him at the one authority that actually knows his engine: the factory service manual, free to download, for the machine already sitting in your shed.
Your job is to hand him the guide, keep him safe, and check his answers against the keys in the back.
That’s it.
What is A year in small Engine Repair?
Small Engine Repair: A Full-Year Elective 50 pages. Eight units. Thirty-six weeks. Two-stroke and four-stroke.
Built to run at three to five hours a week: about an hour reading, an hour of written work, and one to three hours in the shop with an actual engine in pieces.
| Unit 1 | Safety, Tools & Knowing Your Engine (weeks 1–3) |
| Unit 2 | How an Engine Works (weeks 4–8) |
| Unit 3 | Engine Anatomy: Parts & Assemblies (weeks 9–13) |
| Unit 4 | Fuel & Air Systems (weeks 14–18) |
| Unit 5 | Ignition & Electrical (weeks 19–22) |
| Unit 6 | Lubrication, Cooling & the Governor (weeks 23–26) |
| Unit 7 | Maintenance, Diagnosis & Troubleshooting (weeks 27–31) |
| Unit 8 | Teardown & Rebuild: The Capstone (weeks 32–36) |
By May, your student takes a dead engine completely apart, measures every wearing part against factory service limits, laps the valves, sets the camshaft timing, torques every fastener in sequence, and starts it.
Use Digitally or Printed
This is a PDF printable resource that you can use on a tablet, phone, computer, or other device, OR you can print it out and have it bound yourself for a pen-and-paper version.
No hard copy will be mailed to you.
The Diagrams
Thirteen diagrams drawn by hand for this guide, in ink line art. Not stock clip art and not photographs of somebody else’s engine.
Each one has numbered callouts and blank label lines beneath it:
- The four-stroke cycle across four panels — the student reads the piston, the valves, and the flow arrows, and names each stroke themself
- The two-stroke cycle with all three ports
- A full engine cross-section with twenty callouts
- The valve train drawn at a true 2:1 gear ratio, so the half-speed camshaft is something they can see rather than something they are told
- Float-bowl carburetor with fourteen callouts, plus a separate venturi diagram
- The magneto, the spark plug, splash lubrication, air cooling, the governor and its linkage
Every one has an answer key in Appendix F.
What’s in the back?
Two appendices exist for you, not for him.
Appendix D holds the answer keys for all eight self-check quizzes. Ninety-six questions across recall, comprehension, and applied reasoning, all answered, with the reasoning spelled out.
Appendix F holds the label keys for all thirteen diagrams.
You can check every piece of work in this course without learning small engines yourself. That was a design requirement, not an afterthought.
What additional Resources Do You Need?
One general textbook
The guide is written to be textbook-agnostic and includes a page on adapting it to whatever book you choose. My recommendation is a used copy of Small Gas Engines by Roth—a $10 to $25 used copy of an older edition does everything a $100 new one does.
One factory service manual
Briggs & Stratton’s single-cylinder OHV manual runs about $20, and many manufacturers publish theirs free as PDFs. This is the book your student will actually live in.
A basic tool kit
Sockets, wrenches, screwdrivers, pliers, feeler gauges. Most homesteads already have eighty percent of it. Units 1 through 5 need nothing beyond the basics; the specialty tools—torque wrench, compression gauge, flywheel puller—can wait until spring and run about $100 together.
A junk engine, free
For the Unit 8 capstone your student needs a four-stroke engine that does not run. Curb, auction, a neighbor’s shed. It doesn’t need to be worth saving. Start looking in the fall so it’s sitting there by February.
Who this is for
- The homeschool parent with a mechanically minded teenager and no way to feed it
- The family with equipment that keeps breaking and a repair bill that keeps growing
- Anyone raising children who should leave home able to fix what they own
- Co-ops and small schools looking for a real elective rather than a video series
Who this is not for
- Anyone wanting a hands-off course their student completes alone at a screen. This one requires a workbench and dirty hands.
- Anyone unwilling to buy one supporting book
- Middle grades. The tools and fuel handling make this a high school course.
Questions People Ask
I don’t know anything about engines. Can I really run this?
Yes, and it was built for exactly that. Every quiz and every diagram has a key in the back. The technical authority in this course is the factory service manual for your own machine, not you. Your role is to hand over the guide, enforce the safety rules, and check the work.
How much high school credit is this?
Thirty-six weeks at three to five hours a week comes to roughly 110 to 180 hours, which covers a full credit under most homeschool record-keeping standards, generously so at the high end. Nobody accredits it, because in your homeschool you are the school. Record it as Small Engine Repair, one credit, elective.
Is this only for boys?
No. There is not a gendered pronoun anywhere in the document. It says “your student” throughout.
My child isn’t especially mechanical. Is this wasted?
The most valuable thing in this course isn’t engines. It’s Unit 7—moving from a symptom to a cause without guessing, checking the cheapest possibility first, and refusing to replace parts until you know which one failed. That habit transfers to plumbing, wiring, livestock, and most of adult life.
Can I use this with more than one student?
Yes. It’s a household license. Print as many copies as you have children. Please don’t share it outside your home or resell it.
What if we fall behind?
The pacing chart is a suggestion, not a schedule. Units 1 through 6 build in order; 7 and 8 need everything before them. Plenty of families will run this over eighteen months and be better for it.
Is it a printable?
Yes. It’s a PDF formatted for letter-size paper. Print the whole thing, or print units as you go. The worksheets are meant to be written on.