Right then, let’s talk about this old bike I picked up. It’s a 1974 Yamaha 350. Been sitting for who knows how long. Got it for a decent price, figured it’d be a good little project to keep my hands busy.
First Look and Getting Started
When I first got it into the garage, it wasn’t pretty. Looked complete, mostly, which is always a plus with these older machines. But covered in dust, grime, you know the drill. Tires were shot, flat and cracked. Seat foam was basically dust under the ripped cover. The usual stuff.
First order of business was just getting a feel for it. Checked if the engine turned over. Stuck solid. Okay, knew that was coming. Checked the tank – rusty inside, of course. Brakes? Well, the levers moved, but didn’t feel like they were doing much. Electrics looked like a rat might’ve had a party in there.
The Teardown Phase
So, I started taking things apart. Always best to go slow, take pictures, label stuff. Learned that the hard way years ago.
- Wheels off first. Makes it easier to move around.
- Tank and seat came off next. Revealed more grime and some frame rust, but nothing too serious.
- Pulled the exhaust pipes. A bit banged up but solid.
- Then tackled the engine. Disconnected carbs, wiring, clutch cable, chain. Undid the mounting bolts. Had to wiggle it a bit, but it came out. Always heavier than you expect.
With the engine on the bench, I could really see what was up. Pulled the top end off. Yep, pistons were stuck tight in the bores. Probably water got in there somehow. The barrels didn’t look too scored though, which was good news.
Cleaning, Fixing, Finding Parts
This is where the real work starts. Lots of cleaning. Degreaser, wire brushes, scrubbing away years of neglect. Cleaned the frame up best I could without stripping it bare this time.
Got the engine unstuck. Lots of penetrating oil, patience, and some careful tapping. Honed the cylinders lightly myself, they cleaned up okay. New piston rings were a must. Found some online without too much trouble, thankfully. Also grabbed a full gasket set.
The carbs needed a serious deep clean. Took them completely apart, soaked them, blew out all the tiny passages. Put new jets in just to be safe. Finding decent replacements for rubber bits like intake boots was a bit of a hunt, but got there eventually.
Wiring was less fun. A lot of brittle wires and dodgy connections. Spent a good afternoon with a multimeter, soldering iron, and heat shrink, tidying it up. Replaced the spark plug caps and plugs too.
Cleaned the rust out of the tank using some vinegar and shaking it around with nuts and bolts inside. Rinsed it thoroughly afterwards. Not perfect, but way better. Put an inline fuel filter on just in case.
Putting It Back Together
Reassembly is usually the fun part. Engine went back into the frame. Bolted everything up. Reconnected cables, chain, wiring. Put the cleaned carbs back on. New air filters too, the old ones were toast.
Fitted the exhaust pipes with new gaskets. Put the tank and seat back on loosely. Hooked up a temporary fuel line. Checked the oil injection pump seemed okay, but pre-mixed the first tank just to be super safe.
Wheels went back on with new tires and tubes. Lubed the chain. Checked the brakes again – needed bleeding and adjusting, but they seemed functional now.
The Moment of Truth
Okay, moment of truth time. Fuel on. Choke on. Ignition on. Gave it a few kicks. Nothing. Checked for spark – yep, got spark. Checked fuel – yep, plugs were wet. Kicked it a few more times. A cough! Then another. Then, vroom! It fired up. Smoked like hell, like these old two-strokes do, especially after sitting.
Let it warm up a bit, fiddled with the idle screw. Sounded pretty rough but it was running. That’s always a good feeling. Shut it down, checked for leaks. Seemed okay.
Finishing Touches
Still needs proper tuning, synching the carbs, setting the timing properly. And need to sort out that seat cover properly. But it runs and moves under its own power. Took it for a quick spin up the driveway and back. Brakes work, shifts through the gears. It’s alive!
It’s been a decent process. These old Yamahas are pretty straightforward to work on, parts aren’t impossible to find if you look around. Good solid bikes from that era. Happy with how it’s turning out so far. Just need some more time for the final fiddly bits.
