Rebuilding a Lawnmower Engine for Dummies - The Freelance Files MMCXI

small engine parts

One of the staffers was griping about his string trimmer recently and stated that he would "Never, never, never buy a gas-powered trimmer again." A couple of days later he sheepishly admitted that he had spend a few bucks at a local BigBox to get a carburetor adjustment tool, and his trimmer was running just fine now, thank you. We submit that even that experience is more than the minimal knowledge displayed by returning DotD Tom Lutzenberger, who failed to pay attention to a critical word in his GardenGuides.com attempt to explain "How to Rebuild Lawn Mower Engines."

The word Tom glossed over was "rebuild." We read through his instructions, and we realized that something was missing. So we visited an authority on the topic of internal combustion engines, and here's what YourMechanic.com had to say about the process of rebuilding an engine:

"A rebuilt engine involves removing the engine from the vehicle and completely disassembling it ... Once the engine has been disassembled, cleaned, and inspected, all damaged parts are replaced [bolding ours] with new or refurbished replacement parts." Interestingly enough, Lutzenberger cited a reference (for small engines) that said pretty much the same thing; including sections about "inspecting parts" and "ordering parts." In other words, an experienced mechanic (small- or large-engine) would outline the rebuild procedure as follows:

1. Disassemble entire engine
2. Assess all parts for damage or excessive wear; repair or replace parts as necessary
3. Clean and lubricate all parts
4. Reassemble engine

On the other hand, Lutzenberger's procedure consists of

1. Disassemble complete engine
2. — [this space left blank] —
3. Clean and lubricate all parts
4. Reassemble engine.

Nowhere did our Dumbass of the Day (now receiving award number fourteen here) say anything about repairing and replacing parts, even though two of the three references he supposedly used specifically mentioned the step (and the third said nothing at all about engine rebuilds). Oh, wait: we forgot Tom's Step Number 5:

"Attach a new air filter and oil filter, and throw away the old ones. Insert a new spark plug into the cylinder and tighten it down carefully with the socket wrench..."

Uhhh, sorry, Tom: those procedures aren't part of rebuilding an engine, they're normal maintenance; except that lawnmowers don't usually have oil filters...

DDIY - SMALL ENGINES