Project #2. 07 Ttr125le

Oh my. I got myself into it this time. I found a TTR125 listed for $250. She was a little beat up, but I went to look.

First thing I see is it's missing the battery, kick, and front brake lever. Tried the rear brake, nothing there either.

So I want to check compression. I put it in gear and... Nothing, tire just slides. Put it in its highest gear and still tire just slides. Now I'm no mechanic, just a dabbler, but I think this crank is seized. Sniffed the oil dip, smells like transmission fluid. Definitely seized if they put transmission fluid in the engine!

I called up and asked a buddy, he said check the frame, if looks good may be ok for a project. Frame looks really good surprisingly, so I offer $150.

Loaded her up and brought home.

Now on to disassembly. I've gotta get the engine out because I am pretty sure I've gotta split the crank case to have any chance here, and the engine is my first priority; I'm not spending any money on anything else unless I can get this engine running. I've never done this before!

First steps first. Research. Watched maybe 10 hours of engine rebuild videos at 2x speed. Learned a few tips like using heat to expand metal, tools to buy, etc. I've listed tools and parts bought at the end of this article.

Get the service manual. Check! Thank you internet!

Disassembly time! Seat, fairings, tank removed. Engine mounts and engine out.

Now to pull the timing gear and head off.

Here's the head showing all the buildup on the valves.

Now the cylinder is off. I was hoping the piston was stuck in the cylinder and crank was good, but no such fortune. New crank ordered. The OEM one is over $400!!! Not doing that. Turns out the YBR125 is an identical engine, and there is a new aftermarket crank available for it for $65. Ordered it and an oil seal kit. Going to wait until I can get the bearings out to determine if I need to order all of them...

Next comes the side covers, clutch and basket, kick start shaft, starter motor, and drive gear. Then flywheel.

The flywheel bolt was rough. Had to resort to my air impact gun. The flywheel was even rougher. The flywheel puller started to splay the crankshaft in two!

Finally it popped! And I instantly learned the starter clutch was toast. New aftermarket one ordered.

Next comes splitting the crankcase, bearings, etc. That will be part 2.

Parts:
$30 Starter Clutch for Yamaha TTR125E TTR125LE 03~07 XT125R XT125X 4TU-15590-00-00
$9 For Yamaha YBR125 5VL Engine Oil Seal Rubber Gear Shaft Oil-proof Set Motorcycle
$65 Engine Crankshaft Crank Shaft Version Fit For Yamaha YBR125 JYM 2002 2003 2004
$19 Full Gasket Kit Yamaha YBR125

Tools:
$128 Tusk Crank Case Splitter Separator And Crank Puller Installer Tool Dirt Bike ATV
$12 IRWIN VISE-GRIP Convertible Snap Pliers, 6-1/2-Inch (2078900)
$25 Tusk Clutch Holding Tool
$65 ARES 71000-43-Piece Harmonic Balancer Puller Set - Use with Harmonic Balancers, Steering Wheels, Crankshaft Pulleys and Gears (for pulling the Flywheel)
$37 Supercrazy 9PCS Blind Hole Pilot Bearing Internal Extractor Puller W/ Slide Hammer Removal Tool Kit
$33 Ivation Trigger Start Propane Torch, High-Temperature Flame Torch [2372°f] w/Easy Trigger-Start Ignition & Adjustable Flame Control
$12 Kichwit 4 Inch Drill Power Brush Tile Scrubber Scouring Pads Cleaning Kit, 2 Inch Small Brush Included, Heavy Duty Household Cleaning Tool
$7 Lisle 14000 Parts Cleaning Brush