1. Parts
  2. Engine

1999 Yamaha YZ125 Engine

1999 Yamaha YZ125
Tire Size:
Front: 80/100-21, Rear: 100/90-19
Spark Plug:
BR9EG
Battery:
NA
Stock Chain/Belt:
520x112
Stock Gearing:
Front: 13T, Rear: 48T
Oil Filter:
NA
Select Your Ride: Go

Refine
Reset
Sort By:
Grid List
Wiseco
Top End Kit
$82.79 - $251.09
You save up to $83.70 (25%)
(20)
Wiseco Top End Kit Wiseco-forged high-silicon aluminum alloy pistons are computer-machined to exacting tolerances Designed for greater strength with reduced weight and improved heat transfer Pisto...
Wiseco
Pro Lite Piston Kit
$64.00 - $194.99
You save up to $45.96 (19%)
(12)
Wiseco Pro Lite Piston Kit Available for both two stroke and four stroke bikes, the Wiseco Pro Lite Piston Kit is both a great OEM alternative and an easy way to boost the power. Choose stock bore ...
Wiseco
Complete Bottom End Rebuild Kit
$461.21
You save $153.74 (25%)
(12)
Wiseco Complete Bottom End Rebuild Kit Each kit contains everything you need to complete your rebuild the right way, the first time- crankshaft and connecting rod, all applicable bearings, and comp...
Athena Complete Gasket Kit Manufactured in "State-of-the-Art" computer controlled facilities All gaskets made from the highest quality materials All gasket sets meet or exceed OEM specifications T...
Moose Racing Top End Gasket Kit Performance sets designed for a piston replacement Top-end gasket sets include high-performance head, base, intake and exhaust gaskets Cost-effective way to rais...
Moose Racing Complete Gasket Set All gaskets needed for engine rebuild are included in each set with the exception of oil seals Unmatched reliability and performance from high-tech materials Des...
Namura Technologies Top End Repair Kit Namura Technologies piston kits are direct replacements for OEM piston with no modifications or dimensional adjustments needed. Combine this with the MOS2 coa...
Hot Rods Connecting Rod Affordable premium quality replacement connecting rods Forged from 8620 AISI steel, hardness tested to insure strength and durability AISI carburized crankpin ...
Moose Racing
Cast Piston
$51.95 - $196.95
(0)
Moose Racing Cast PistonGravity cast aluminum alloy with 18% silicon to increase resistance to wear and decrease thermal distortion, thus providing a longer piston life Coated skirts ease break-in...
Wiseco
Replacement Ring Set
$12.96 - $29.99
You save up to $7.90 (20%)
(2)
Wiseco Replacement Ring Set Wiseco offers a complete range of popular piston models and years for both trail and racing applications Durability, longevity and increased horsepower Each ring set ...
Wiseco Top End Bearing When you replace your top end a new Top end bearing is a must. With a new Wiseco Top End Bearing it will keep that wrist pin and rod working perfectly when you put it to...
Moose Racing Countershaft Seal Kit Kit includes hardened steel bushing, an upgraded seal, an O-ring (where applicable) and a snap ring or lock washer (where applicable) Made in the U.S.A.
Vertex
Piston Kit
$49.99 - $247.99
You save up to $2.00 (3%)
(1)
Vertex Piston Kit Restore that crisp clean power that your dirtbike or quad use to have with a new Piston Kit from Vertex. Or step up the power with a high compression Piston Kit, All kits are...
Moose Racing Magnetic Drain Plug Prolong engine life and save on costly repairs with an oil plug that picks up metal filings Must use washer provided Compare with original OEM plug befo...
Athena Race Gasket Kit For the true Racer. Racers depend on reliability, performance and of course affordability, that's exactly what you get in Athena's new Race Gasket Kits Kits include a multi-l...
Hammerhead Designs, Inc.
Oil Filler Plug
$22.46 - $53.96
You save up to $5.99 (9%)
  • Gold
  • Blue
  • Black
  • Red
(0)
Hammerhead Designs Oil Filler Plug6061 T-6 Machined Billet Aluminum with an anodized finish and O-ring seal Laser etched Logo adds a nice factory look All models are plug only (No Dipstick) unles...
Hot Rods Main Bearing and Seal KitPrecision, high-quality main bearing and seal kits complement Hot Rods crankshaft assemblies All kits contain two main bearings and two seals Work for rebuilding ...
Works Connection Oil Filler Plug 6061 T-6 Aluminum with an anodized finish and O-ring seal Adds nice factory look Made in the USA **Note: Honda CRF450R models must order one for crankcase and one...
Wiseco Connecting Rod Double forged, connecting rods maintain superior dimensional consistency through improved grain flow. Shot peening eliminates residual stresses and smoothly blends the rod f...
Hot Rods
Crankshaft Assembly
$152.96 - $552.46
You save up to $97.49 (14%)
(1)
Hot Rods Crankshaft Assembly All new assembly sold complete with Hot Rods connecting rod Factory assembled and trued to OEM specifications, Hot Rods cranks will meet or surpass the OEM in perf...

Latest Reviews

Jay (Busselton )

Fit
Finish
Durability
Features
Cost Benefit

Full engine gasket set

Good kit for my RM 250 1993 project/rebuild. The team at Motorcycle Superstore were extremely helpful!

Clayton (Syracuse )

Fit
Quality
Installation
Recommend

hot rods complete bottom and rebuild kit

Rebuilt my 2007 kx85 with the hot rods complete bottom and rebuild kit, so far no problem whatsoever. Really satisfied with it.

grayson (edmonton )

Fit
Quality
Installation
Recommend

works fine

Went in okay. One of the top o-rings was a pain in the ass, but it seemed to work out in the end. It recomended drilling a hole, but my old piston didn't have one, so I didn't feel like drilling my brand new piston.

Bryan (Hayden )

Fit
Quality
Installation
Recommend

its f****d

Had my brand new Wiseco top and bottom end put in about a month ago in my 2002 Honda CR250r. Less than 10 hours and changing my fluids twice bottom end seized yet again. Biggest piece of crap I've spent my money on, wouldn't recommend AT ALL.

randy j. (sand lake )

Fit
Quality
Installation
Recommend

flywheel weight

Works great- just right for the YZ250 for woods riding.

;
Back to Top