Yamaha PW50 60cc Big Bore Kit 1981-2009

Yamaha PW50 60cc big bore kit with cylinder, head, piston, gaskets, studs and spark plug

Yamaha PW50 60cc Big Bore Kit 1981-2009 – Cylinder, Head, Piston, Gaskets & Studs Top End Kit

Dhs. 310.52

Yamaha PW50 60cc Big Bore Kit – Complete Top End for 1981–2009 Models

This Yamaha PW50 60cc big bore kit replaces the stock top end on the little two-stroke PW50 with a larger cylinder and everything needed to fit it. It is listed for PW50 models from 1981 through 2009. In the box you get a cylinder block, cylinder head, piston, rings, pin, small end bearing, gaskets, studs, nuts and a spark plug, plus gasket maker and thread lock for assembly. Easy Life Markets sells it as a complete kit, so you are not left hunting for a missing gasket halfway through the job.

The Yamaha PW50 is one of the most popular first bikes for young riders, and plenty of them have been passed down through families and ridden hard for years. Yamaha still sells the current model, and you can see it on the official Yamaha PW50 page. When the original top end is worn out, many owners take the chance to fit a 60cc big bore cylinder instead of a stock replacement.

Why Riders Fit a PW50 Big Bore Kit

There are two common reasons to buy this kit. The first is repair: a PW50 that is hard to start, has lost compression, or has a scored cylinder needs a new top end anyway. The second is growth: as a young rider gets more confident, a larger bore can give the bike a bit more pull than the stock 50cc setup. Either way, you are replacing the parts that wear most on a two-stroke engine in one go.

Typical signs that your PW50 top end needs attention include:

Hard starting or no start, even with a good spark plug and fresh fuel
Low compression when you kick it over
Noticeably less power than it used to have
Scoring or damage on the cylinder wall or piston
Rattling or knocking from the top of the engine

What Is Included in the Kit

1 x cylinder block
1 x cylinder head
1 x piston
2 x piston rings
2 x circlips
1 x piston pin
1 x pin bearing (small end bearing)
1 x head gasket
1 x base gasket
4 x cylinder studs
4 x stud nuts
1 x spark plug
1 x gasket maker
1 x thread lock

The product photos show the cylinder, head, piston and hardware laid out so you can compare them with the parts on your bike.

Specifications

Product type: Big bore cylinder top end kit
Displacement: 60cc big bore
Listed fitment: Yamaha PW50, 1981–2009
Engine type: Two-stroke, single cylinder (PW50)
Cylinder and head finish: Black, finned, as pictured
Kit contents: 22 pieces in total (see list above)
SKU: CJQT301229301AZ

Fitment Notes

This kit is listed for the Yamaha PW50 from 1981 to 2009. Before ordering, confirm the model and year on your bike's frame plate or paperwork. If the bike has already been modified, for example with a different intake, reed block or exhaust, compare the port layout and gasket shapes in our photos with your current parts. If anything looks different, contact us before ordering and we will help you check.

Keep in mind that a bigger bore changes how the engine breathes. Many riders find the carburetor jetting needs a small adjustment after fitting a big bore kit, so check the spark plug color after your first few rides and adjust if the bike runs rich or lean.

Installation Tips

Fitting a PW50 top end is one of the easier engine jobs, and many parents do it at home with basic hand tools and a service manual. A few points to help it go smoothly:

Clean the crankcase gasket surface carefully and stuff a clean rag into the crankcase opening before removing the old circlips.
Fit the new pin bearing in the connecting rod small end, then the piston and pin, and make sure both circlips click fully into their grooves.
Line up the ring end gaps with the locating pins in the piston grooves. Two-stroke rings must sit on their pins or they can snag a port.
Oil the piston, rings and bore with two-stroke oil before sliding the cylinder on.
Use the supplied thread lock on the studs and tighten the head nuts evenly in a cross pattern to the torque in your service manual.
Run the engine gently for the first few rides to let the new rings bed in.

Getting the Most from Your New Top End

A fresh big bore cylinder will last longer if the basics are right. Mix the fuel and two-stroke oil to the ratio in your owner's manual, and use fresh fuel rather than something that has been sitting in a can all winter. Keep the air filter clean and oiled, because dust is the fastest way to wear out a new piston and cylinder on a dirt bike. Check the spark plug after the first few rides to see how the engine is running, and keep an eye on the head nuts and exhaust connection, which can settle slightly once the new gaskets have been through a few heat cycles.

Is This the Right Kit for You?

If your PW50 needs a new top end and you are happy with a 60cc big bore rather than a stock 50cc cylinder, this kit covers the whole job in one purchase. It suits parents keeping a family pit bike running, small shops that service mini bikes, and riders restoring an older PW50. If you want to keep the bike exactly stock, a standard-size cylinder kit would be a better choice.

Buy the Yamaha PW50 60cc Big Bore Kit at Easy Life Markets

You can order this PW50 big bore kit right here. The current price and availability are shown on this page. Questions about fitment can go to our customer service team, and you can read our return and refund policy before you buy.