Yamaha TTR-125LE Minimoto

Details

The easiest and most cost-effective way to get a lot more track time is to ride a minimoto bike on go-kart tracks. For $50 a day you get as many laps as you can handle to work on technique at low speeds, with low fuel and tire costs, but big fun.

This particular TTR-125 was cheap to buy because it didn’t run, but it did have some expensive aftermarket parts. In essence I bought a fancy pair of wheels and got a free bike.

When it got it home I started going through it top to bottom to make an awesome minimoto bike for weekly sessions on track, and with the help of my friend Ed Sorbo at Lindemann Engineering, I’ve now completed the first phase of work. It runs, it’s great fun, but there is ample room for improvement to make it perform and handle better.

Unusually for me, in this case aesthetics doesn’t matter. It’s probably going to get crashed (a lot), so what it needs is rock-solid mechanicals and handling, the best performance the little thumper is capable of making, and decent protection to stop the controls and engine getting damaged when it goes over.

Phase one:

Cleaned the bike as thoroughly as possible
Checked the wheels are straight / true
Stripped and rebuilt the throttle control (it was sticking open which is sub-optimal)
Had the front forks resprung and revalved for the track instead of dirt
Had the rear shock set up for the track and my body weight
Stripped and cleaned the carburetor
Checked the valve clearances
Greased the steering head bearings which were bone dry
Replaced the spark plug
Replaced the battery with a lightweight lithium ion one
Cleaned the airbox and replaced the filter
Cleaned and inspected the front brake caliper and pads
Replaced the carburetor
Fitted the hand guards
Oil change
Cleaned and lubricated the chain
Removed the skid protector from the bottom of the engine
Bled the brakes
Removed the kick starter
Set the tire pressures and took a test ride
Replaced the broken choke cable
Adjusted throttle free play and idle speed
Adjusted the rear brake
Fitted a bracket for the lap timer
Shakedown test ride at Buttonwillow kart track