The Fiendish Rider Put the book down

The garage

Latest from the shed

Stage 1 of this site went live 21 July 2026. Two bikes in the garage; both online.

Garage card YZ125 2016

YZ125 2016

About The Bike

Last updated: 6 August 2026

Identity

  • Make: Yamaha
  • Model: YZ125
  • Year: 2016, confirmed via VIN 13 July 2026
  • History: owned from new, purchased 2016. Bought with Yamaha's race pack deal of the time: GYTR parts, V-Force 4 reeds, oversized front disc, 49T rear sprocket. Ridden roughly ten weekends in 2016, then long stretches of shed time. Well kept, never ridden hard. Low total hours, no meter history. Mint condition, kept that way.
  • Primary use: the keeper. Long-term vintage bike, not going anywhere. Ridden when the KX is down.
  • Status: In the shed, suspension back from Moto Lab and being refitted. One refit, one sag set and the connecting rod bolt away from current.

Standing-state entries appear below as systems get touched. Stock stays invisible. Sharpie on blank page.

Engine

  • DEP pipe fitted (identified 14 July 2026, race-pack era fitment).
  • V-Force 4 reeds fitted (race pack).
  • Jetting likely needs work. Rider wants to learn jetting on this bike rather than farm it out.
  • Top end NOT due: low gentle hours since new. On a bike with shed years, age items (crank seals, fuel lines, coolant) outrank wear items. None currently symptomatic.

Suspension

  • Rear shock never serviced. Service planned. Sag to be set once it's back in the bike.
  • Fork seals leaking and shagged. Forks pulled 12 July while greasing the steering head. Releasing the air bleed screws brought up puffs of oil mist: oil in the outer chamber where only air should be, internals passing. Full fork service required, not just seals. Spring rates to be checked against rider weight while apart. These forks go to Moto Lab FIRST, ahead of the KX suspension, since this is the bike being ridden.
  • Estimated suspension spend ~$1,000 all in.
  • 14 July 2026. Shock out. Linkage and swingarm greased, all linkage hardware checked tight. Full suspension set (forks + shock) ready to go out for service as one drop-off.
  • 21 July 2026. Full set (forks + shock) out for service.
  • 23 July 2026. Moto Lab's read: not expecting to need new springs, so the suspension estimate likely comes in under the earlier figure. Confirmed on collection.
  • 6 August 2026. Forks and shock back from Moto Lab. Full service and revalve on both ends; existing springs retained on both, no new springs fitted, confirming Louis's read. Fork seal kit, shock oil seal, shaft bushing and dirt scraper seal replaced as part of the rebuild. Sag to be set once refitted.

Front end and bearings

12 July 2026. Steering head bearings greased. Forks out (see Suspension).

14 July 2026. New grips fitted.

Linkage and swingarm

14 July 2026. Linkage and swingarm greased, shock removed. All hardware tight (rear wheel and shock bolts loose by design, suspension out). Watch item: the connecting rod bolt at the frame end was part-seized coming out despite recent grease. Action fine, bearings feel good, likely corrosion between bolt shaft and inner collar. At reassembly: emery the bolt shaft, moly it, replace the collar if it still drags.

Brakes

  • Oversized front disc, race pack item, looks the part. Note for whoever does the bleed: the disc is not stock.
  • Front brake bite point too deep: lever pulls well back toward the bar before anything happens. Rider wants a firmer, earlier bite. Bleed and pad inspection first, master cylinder service if that doesn't fix it.

Drivetrain

  • Original chain and 49T race pack rear sprocket, unworn, being replaced only to enable the longer wheelbase.
  • Ordered MX Store 14 July 2026, $278.89 paid: RK GB520KXZ gold heavy duty chain 120L ($99), Renthal Yamaha Ultralite silver rear sprocket 50T ($119.94), Ballards wireless vibration hour meter ($59.95).
  • Fitment plan: chain cut so the axle sits at the rear of the adjusters WITH the 50T fitted. Gearing goes 49 to 50 rear, 13T front original and staying pending a tooth inspection at fitment.
  • 21 July 2026. Chain, 50T Renthal and hour meter fitted. Chain cut half a link short, axle likely near original wheelbase rather than rear of adjusters. Final rear wheel position to be set once the shock is back in. Acceptable outcome, wheelbase change was a nice-to-have.

Work list (opened 12 July 2026, restructured 14 July 2026)

To current:

  • Suspension refit on return from Moto Lab. Includes the connecting rod bolt: emery the shaft, moly it, new collar if it still drags. Bolt waits until the bike is balanced on the stand for a workable punch-out angle.
  • Sag set after suspension refit
  • Front brake bleed and pad inspection

Done:

  • Chain and 50T sprocket fitment (21 July 2026; final rear wheel position to be set once the shock is back in, see Drivetrain)
  • Hour meter fitted (21 July 2026): zero baseline from the refreshed bike

Standing extras, hold until the big stuff is done:

  • Front disc guard (~$50)
  • Alloy bash plate, replacing current (~$120)
  • Footpegs (~$300)
  • Grip seat cover (~$80)
  • Jetting work (rider learning project)

Estimated remaining spend: suspension ~$1,000 is the main outstanding cost. Chain, sprocket and hour meter now paid ($278.89). Standing extras ~$550.