The stock carburetor on a Yamaha Blaster 200 is a Mikuni VM26 — a 26 mm unit — and the common performance swap is a 28 mm Keihin PWK, which needs adapter and jetting work rather than bolting straight on.
Order the wrong bore and the intake boot won’t seal, the throttle cable won’t reach, or the engine runs dangerously lean on its first tank. Knowing what size carb fits the Blaster 200 before you buy saves a return shipping label and a wasted weekend in the garage. This guide covers the stock size, the popular upgrade, what each one costs, and the fitment checks that decide whether a carb actually works on your machine.
What Size Carburetor Comes Stock On A Yamaha Blaster 200?
The Yamaha YFS200 Blaster left the factory with a Mikuni VM26, which measures 26 mm at the bore. That is the size to match if you want stock-style replacement behavior.
The Blaster ran from 1988 through 2006, and Yamaha’s own documentation identifies the later model as the YFS200V with dedicated carburetor removal and specification sections. Part numbers can vary by model year, so confirm your machine’s year and identification label against factory parts information before ordering. A 26 mm replacement is the closest stock-style fit, and
Will A 28 mm Carburetor Fit The Blaster 200?
A 28 mm Keihin PWK28 fits the Blaster 200 as a performance conversion, not as a guaranteed bolt-on. The larger bore is sold for stock, trail-ported, and modified YFS200 engines, and the seller’s own listing warns it is not an exact replacement for every original Blaster connection.
Expect to handle three things:
- Jetting: the PWK28 ships with a 150 main jet and 48 pilot jet. Treat those as starting components, not final settings.
Going from 26 mm to 28 mm changes airflow and fuel demand. Final jetting has to be confirmed for your exhaust, intake, altitude, temperature, and fuel system — no listing can hand you that number.
What The Numbers Actually Cost
Prices below are listing snapshots and move around, but they show the real spread between a stock refresh and a full conversion.
| Option | Typical Price | What To Expect |
|---|---|---|
| OEM-style Mikuni VM26 refresh kit | About $49 | Closest stock-style fit; reuses factory intake and cable |
| Aftermarket 26 mm replacement | $25.95–$37.98 | Marketplace listings, not Yamaha-authorized |
| Aftermarket 28 mm carburetor | From $68.61 | Cheap conversion; verify fitment and jetting yourself |
| Genuine Keihin PWK28 | $225.00–$254.99 | 28 mm bore; adapter and cable sold separately |
| PWK28 flange adapter | $22.00–$29.99 | Mates carb to the stock air-cleaner joint |
| Optional thumb-throttle cable | +$14.99 | Needed when the stock cable won’t work |
| Haynes YFS200 service manual | From $37.45 | Covers 1988–2006 carb servicing, float adjustment, rejetting |
If you are still weighing brands, this roundup of tested Yamaha Blaster carburetor picks compares the stock-style and conversion options side by side. For the procedure itself, the Haynes YFS200 service manual walks through float adjustment and rejetting for the full 1988–2006 range.
How Do You Swap The Carburetor Without Creating New Problems?
Yamaha’s owner’s manual lays out a short removal sequence: turn the fuel cock to OFF, loosen the carburetor clamps, disconnect the fuel hose and oil hose, loosen the clamp screws on each side and pull the carburetor, then disconnect the throttle cable from the throttle valve by removing the holder screws and holder.
Reversing that gets you most of the way back, but the mistakes that bite happen before and after the install:
- Ordering by engine displacement alone without confirming model year, intake-joint dimensions, air-box connection, cable arrangement, and hose locations.
- Assuming the supplied jet set is correct for your exhaust and altitude.
- Skipping the air-leak check, float height check, and full-throttle slide-opening check.
- Trusting generic “OEM specification” marketplace wording as proof of Yamaha authenticity.
Keep the engine cool and the fuel supply shut off while working — fuel leaks and vapors are a fire hazard. Once it’s back together, confirm the throttle snaps fully closed before starting, the fuel system shows no leaks, and the engine isn’t running lean. An intake leak or a sloppy oil-injection connection can damage the engine fast. The manual also notes carburetor settings may need adjustment in extremely cold weather to keep performance steady.
Common Questions
Is the stock Blaster carburetor 26 mm or 28 mm?
The stock unit is a Mikuni VM26, so 26 mm. The 28 mm figure comes from the Keihin PWK28, which is a performance upgrade rather than the factory size. If you want the machine to behave the way it did on the showroom floor, a 26 mm replacement is the closer match.
Do I need to rejet after swapping to a 28 mm carb?
Yes. A larger bore changes airflow, so fuel delivery has to follow. The 150 main and 48 pilot jets shipped with a PWK28 are starting points only. Your exhaust, intake, altitude, temperature, and fuel system all shift the final numbers, so plan on testing and adjusting.
Can I run a bigger carburetor without other engine work?
You can, but the gains are limited and the tuning risk is real. A 28 mm carb on an otherwise stock engine mostly rewards careful jetting and a leak-free install. Add porting or an exhaust first if you want the extra airflow to actually pay off.
Sources
- Haynes Manuals. “Yamaha YFS200 Blaster ATV (1988–2006) Service Repair Manual” Covers carburetor servicing, float adjustment, and rejetting for the full model range.
- Yamaha. “Blaster YFS200V Owner’s Manual” Source of the carburetor removal sequence and cold-weather setting note.
- Cyclepedia. “Yamaha Blaster YFS200 ATV Online Service Manual” Additional YFS200 service documentation for carburetor work.