Alright folks, grab a coffee, this one’s a journey. So picture this: dust-covered crate arrives, shipped clear across the country. Paid a pretty penny sight-unseen, relying on blurry auction photos like a total newb. Opening it felt like Christmas, mixed with sheer terror. Inside? A grimy, oily, lump of 1937 Knucklehead history, looking more like boat anchor than a motorcycle motor.
The First Look & Taking Things Apart (Way Down!)
Started simple. Just stared at the darn thing for a good hour, trying to figure out where the heck the top and bottom even were. Oil and grime cemented everything together. Gloved up, grabbed some basic wrenches – the absolute wrong size first, naturally. Wrestled the oil drain plug loose; black sludge poured out like molasses, smelled horrible. Took photos of EVERY step with my phone, labeling bolts in jars like my life depended on it. No fancy memory here.
The Big Teardown Begins (Panic Ensues)
Engine needed to come right off its stand. Needed a buddy – called Steve over. “Don’t drop it!” I yelled, uselessly, as we heaved it onto my workbench. Bench groaned. Started peeling layers:
- Ripped off the crusty exhaust pipes, fighting seized nuts with penetrant oil and brute force.
- Unbolted the cylinder heads – oh man, the pistons looked awful, totally gummed up, rings probably welded solid. Scraped chunks of carbon off.
- Got down to the crankcases. This part felt sacred. Carefully split the cases using a soft mallet and pry bars, prying gently bit by bit. Heart pounded. Felt like opening a tomb.
Inside was… surprisingly okay? Main bearings felt gritty though. Journals had some scratches.
The Cleaning Nightmare (So. Much. Crud.)
This was the real work. Days disappeared. Set up bins:
- One for parts needing chemical bath (grocery store degreaser + kerosene mix – cheap!). Soaked valve covers, tappets, you name it.
- One for parts demanding elbow grease. Wire brushes, toothbrushes, dental picks. Scraped carbon for hours. Felt like an archaeologist.
- Special soapy bath for the crankcases and cylinders, scrubbed til my arms ached.
Drying everything took forever. Laid parts out on old towels. My garage smelled like a mechanic’s nightmare for weeks.
Slowly Putting Humpty Dumpty Back Together (Less Broken)
Felt overwhelmed staring at all the cleaned bits. Started simple. Laid out new gaskets everywhere they belonged. Slathered assembly lube on crankshaft bearings like it was butter. Carefully lowered the crank back into the bottom case half. Tapped the new main bearings in gently with a socket.
Mating the case halves? Sweaty palms time. Clean surfaces, fresh sealant. Lowered the top half slowly, praying bolts lined up. They did! Tightened bolts evenly, in sequence, to spec (looked up torque values online). Big milestone.
Pressed in new valve guides using a simple hand press and pipe sockets. Ground the valves myself with paste – messy but satisfying. Reassembled the heads, careful with valve springs.
Installed pistons with new rings, fiddling with ring compressors. Getting cylinders over those pistons? Wrestled. Used grease, tapped gently with a wood block.
Finishing Touches & That First Turn
Bolted the heads down, reconnected pushrods and adjusted those tricky tappets by the manual’s vague description. Installed the oil pump (new gears!), pan, and timing cover with fresh gaskets. Found crusty old plugs, put in new ones.
Primed the oil pump by hand with a drill adapter – spun it til oil seeped out the rockers. Held my breath. Hooked up a tiny battery. Hit the starter button. Nothing. Heart sank. Jiggled wires. Pushed button again… Cough! Pop! Pop! Then silence. Adjusted timing, fiddled with ignition wires… Tried again. Engine sputtered, spat fumes, then settled into a ragged, glorious idle! Oil pressure gauge jumped. Unbelievable sound. Grinned like an idiot.
Is it perfect? Hell no. Still leaks a bit. Needs tuning. But it runs! Did it by the seat of my pants, made a ton of mistakes, learned heaps. Worth every greasy knuckle. On to the frame next…
