Yamaha's engine range spreads wider than any other Japanese brand. The same catalog has to serve a five-valve motocross head from the early YZ-F era, a four-valve underbone head that moves by the container in Southeast Asia, a scooter head for the Cygnus family, and a two-stroke head for the RX platforms still running daily in India. These platforms share a badge and nothing else — different seat layouts, different chamber geometry, different failure patterns — so we catalog every generation as its own part number, cross-referenced to the original casting number.
Our Yamaha aftermarket range covers motocross and enduro platforms — applications for YZ250F, YZ450F and the WR-F enduro variants — underbone and scooter heads for LC135, Crypton, Aerox and Cygnus engines, commuter heads for YBR125 and the FZ and R15 families, ATV heads for Warrior, Raptor, Blaster and Banshee, and two-stroke heads for the RX and DT series. Heads ship as bare castings with seats and guides fitted, or as complete assemblies built to your component specification.
Casting, heat treatment and machining run in our own facility, and every batch carries dimensional records against the part number. Off-road platforms are detailed further in our dirt bike category; high-volume commuter platforms in the commuter bike category.
YZ250F Four-Valve Head
Low-pressure cast A356, T6 treated; covers the four-valve DOHC generation with sintered seats specified for titanium valve contact.
YZ450F Five-Valve Head
The early five-valve Genesis layout places five seats in a compact chamber; sequenced seat pressing protects the thin webs between counterbores.
WR250F/WR450F Enduro Heads
Enduro variants differ from the YZ line in breather and decompression details; we catalog WR and YZ as separate part numbers, never as one shared casting.
YZ125/YZ250 Two-Stroke Heads
Two-stroke heads machined from the solid after casting, with squish band width and chamber volume held to drawing.
LC135 Four-Valve Head
The LC135 platform sells as Sniper, Spark, MX King, Jupiter and Exciter depending on the market; one engine family, several badge variants, all cataloged here.
Crypton/T115 Head
Underbone commuter heads for the Crypton family, including the T-one-fifteen generation, with hardened seats fitted for low-grade fuel.
Aerox 155 Head
The Aerox one-five-five runs Yamaha's variable valve actuation head; we produce it to the original specification including the VVA mechanism interfaces.
Cygnus 125 Head
Four-valve scooter head for the Cygnus one-twenty-five family, a high-volume platform across Taiwan and Southern Europe.
YBR125 Head
Yamaha's global commuter single, sold on every continent with year variants that we catalog separately by casting number.
FZ16/Fazer Head
The FZ family head serves India's largest Yamaha street segment, produced on short-cycle lines for volume channels.
YZF-R15 V3 Head
The R15 V3 runs a high-compression four-valve head with VVA; chamber volumes are held tight and recorded per batch.
MT-15/MT-125 Head
Shares the R15 engine architecture under the MT badge; cataloged with the same variant discipline as the faired version.
Warrior/Raptor 350 Head
The Warrior and Raptor three-fifty share one of the longest-running ATV engines ever built; replacement demand is steady and our tooling is fully amortized.
Raptor 660R/700 Head
Big-bore single heads for the Raptor six-sixty and seven-hundred, with reinforced exhaust-side wall thickness for their heat load.
Blaster YFS200 Head
Two-stroke ATV head for the Blaster, machined with squish geometry to drawing; a favorite of the performance rebuild trade.
Banshee 350 Heads
The Banshee twin takes a pair of two-stroke heads per engine; we supply matched pairs with chamber volumes measured on both.
RX100/RX135 Heads
The RX series remains a daily rider across India and Southeast Asia; heads keep the original squish geometry for tolerance to low-grade fuel.
DT125/DT175 Heads
Trail two-stroke heads for the DT family, a restoration staple with year variants cataloged by casting number.
RD250/RD350 Heads
Twin two-stroke heads for the RD family, supplied as matched pairs for the restoration and classic racing channels.
Virago XV Family Heads
V-twin cruiser heads for the Virago family from two-fifty to eleven-hundred, covering the casting families Yamaha revised across production years.
| PLATFORM | ENGINE | VALVE CONFIGURATION | COOLING | SUPPLY VERSION |
|---|---|---|---|---|
| YZ250F / YZ450F | Four-stroke single | Four-valve DOHC (early: five-valve) | Liquid-cooled | Bare / Complete |
| WR250F / WR450F | Four-stroke single | Four-valve DOHC | Liquid-cooled | Bare / Complete |
| YZ125 / YZ250 | Two-stroke single | Reed valve | Liquid-cooled | Bare |
| LC135 (Sniper / MX King / Jupiter) | Four-stroke single | Four-valve OHC | Liquid-cooled | Bare / Complete |
| Aerox 155 / NVX | Four-stroke single | Four-valve OHC with VVA | Liquid-cooled | Bare / Complete |
| Cygnus 125 / Crypton | Four-stroke single | Two-valve / four-valve OHC | Air / liquid-cooled | Bare / Complete |
| YBR125 / FZ16 | Four-stroke single | Two-valve OHC | Air-cooled | Bare / Complete / CKD |
| YZF-R15 V3 / MT-15 | Four-stroke single | Four-valve OHC with VVA | Liquid-cooled | Bare / Complete |
| Warrior / Raptor 350 / 660R / 700 | Four-stroke single | Two-valve OHC | Air-cooled | Bare / Complete |
| RX100 / RX135 / DT / RD | Two-stroke single / twin | Piston port / reed valve | Air-cooled | Bare / Complete |
Production starts in our foundry with A356 aluminum, cast by low-pressure or gravity die casting depending on the head's geometry. After T6 heat treatment, heads move to CNC machining for seat cutting — including offset seat layouts — guide honing, deck surfacing and cam journal boring, on the same process chain described on our cylinder head machining page.
Inspection runs inside the flow: CMM sampling, leak testing on combustion and water jackets, deck flatness checks, with results filed against the part number. That record is what makes our variant cataloging meaningful — a reorder of an LC135 or a five-valve YZ-F head arrives to the same specification every time, across years of repeat supply.
Both, as separate part numbers. The five-valve Genesis generation and the later four-valve design differ in seat layout, chamber shape and cam drive, and they are tooled and cataloged independently. Tell us the model year range your market serves and we confirm which generation applies before quoting.
In most cases, yes. Yamaha part numbers follow a consistent structure in which the first characters identify the model family — a five-N-L prefix, for example, belongs to the early YZ250F family. Send the OE number and we can usually start drawing work from it; a casting number or sample settles any remaining doubt.
By engine family, not by badge. The LC135 sells as Sniper, Spark, MX King, Jupiter and Exciter across different markets, and badge names tell you nothing about the combustion chamber specification. We catalog by engine code and cross-reference every regional name to it, so your order lands on the correct variant regardless of what the local market calls the bike.
No. WR enduro variants differ from their YZ counterparts in breather layout, decompression details and cam timing interfaces. We catalog WR and YZ as separate part numbers, and we recommend distributors stock both where their market mixes the two — mis-listed enduro heads are among the most common return items in this segment.
Yes. Complete assemblies can be built with standard or upgraded valves, springs, retainers and seals to a component list you approve. For racing-channel customers we assemble to specification and leak-test every assembly before packing.
The OE part number or the casting number from the original head is the fastest route. Engine code, model year and photos of the old part help with regional variants, and for the two-stroke platforms a sample settles squish and chamber questions definitively.
Yamaha coverage looks simple from a catalog page and is anything but simple in a warehouse. Seven platform families, regional badge variants, and two valve-train generations all move under one brand name. The notes below reflect how experienced buyers source Yamaha heads, and they apply to any supplier you evaluate.
Most brands concentrate on one or two market segments. Yamaha competes in almost all of them: championship motocross, mass underbones in Southeast Asia, scooters, commuters, ATVs, and a two-stroke legacy that still moves daily volume in India. For a distributor this is an opportunity — one brand relationship can anchor several stock programs — and a discipline problem, because the platforms share nothing but the badge. Seat layouts, chamber geometry and failure patterns differ completely, and a supplier who treats Yamaha heads as interchangeable will cost you returns.
Yamaha's part numbering is more systematic than most, and learning one rule saves most fitment errors: the first characters of the part number identify the model family the part was designed for. A head carrying a five-N-L prefix belongs to the early YZ250F family, regardless of what bike the seller found it on. The casting number on the original part is therefore the fastest identification route — faster than the bike's badge, because the same engine family ships under different model names in different markets, and different engines occasionally ship under similar names. Where the casting number is unreadable, the engine code on the crankcase identifies the family, and valve count plus cooling type narrows the rest.
| OPTION | WHAT YOU GET | RISK PROFILE | BEST FOR |
|---|---|---|---|
| New aftermarket casting | New casting machined to spec, hardened seats fitted | Low — zero accumulated fatigue | Distributors, rebuilders, fleet channels |
| Used original head | Salvaged part, unknown heat and stress history | High — cracks and prior repairs common | Budget retail, rare variants |
| Machine-shop repair | Original head, seats and guides replaced | Medium — depends on casting condition | Sound castings with localized wear |
The five-valve generation deserves a specific note. Service pricing across the repair trade runs highest on five-valve heads — more seats, more guides, more labor — and a full five-valve seat and guide job on a tired casting approaches the cost of a new aftermarket head. When the casting also shows web cracks or deck warpage, replacement wins on both cost and reliability, which is why rebuilders increasingly stock new five-valve castings rather than sending work out.
The traps repeat across markets. The LC135 engine sells as Sniper in one country, MX King in another, Jupiter and Exciter elsewhere, and badge names say nothing about chamber specification. The Aerox one-five-five runs variable valve actuation, and heads without the correct VVA interfaces fit nothing. WR and YZ heads look alike and differ in details that matter. Two-stroke heads of the same bore family can carry different squish geometry for different fuel grades. Each of these shows up as a return, and each is avoidable at the ordering stage by cataloging to the engine code rather than the badge — the discipline our own variant system is built on.
Ask how variants are cataloged, because a supplier who lists one head for a platform with four regional variants is selling you future returns. Ask whether seats are cut after pressing, since offset seat layouts punish any shortcut in that sequence. Ask for batch records tied to part numbers, because reorder consistency across years is the whole point of a variant catalog. And ask how the supplier handles a five-valve inquiry — the answer tells you immediately whether they actually produce this generation or buy it in. For off-road platforms see our dirt bike category; for the commuter side, the commuter bike category.
Yamaha, YZ, YZ-F, WR, RX, DT, RD, LC135, Sniper, Spark, MX King, Jupiter, Exciter, Aerox, Cygnus, Crypton, YBR, FZ, YZF-R15, MT, Virago, Warrior, Raptor, Blaster, Banshee and all related model names and OE part numbers are trademarks of Yamaha Motor Co., Ltd. They are referenced on this page for fitment identification only. The products listed here are aftermarket replacement parts manufactured for the global replacement market. They are not original Yamaha parts, and no affiliation with or endorsement by Yamaha Motor Co., Ltd. is implied.
