Complete Cylinders
About Complete Cylinders
The cylinder is the bore that the piston runs in, and its wall wears with use. Scoring, a worn bore or a damaged sleeve shows up as low compression, smoke or lost power, and a new cylinder is the repair. Riders also change cylinders to move to a larger bore. The listings cover Polaris, Kawasaki, Yamaha and Honda machines, including the Banshee and the 250R.
Read the title to see what you are buying. Some listings are a bare cylinder, some are a cylinder kit that is meant to go with a piston, and some are related parts such as stud kits, O-rings and head domes. Standard bore keeps the original displacement. Big bore cylinders have a wider bore and need the matching piston, which raises displacement and often compression, so a retune or higher-octane fuel may be needed. The bore size appears in millimeters in the listing, such as 85.00 or 93.00 mm.
Brands in this category include Cylinder Works, Namura, ModQuad, Moose Offroad and KPMI. Pick your machine in the Ride Finder at the top of the page. You will usually also want Pistons, Rings & Piston Kits and Gaskets, Seals & Kits, and Cylinder Heads and Engine Rebuild Kits & Components are close by, in Engines & Engine Parts.
FAQs on ATV and UTV cylinders
What is the difference between a standard bore and a big bore cylinder?
A standard bore cylinder keeps the engine's original size. A big bore cylinder has a larger diameter, so it needs a matching larger piston and raises displacement. It can also raise compression, so the engine may need tuning, and it should be used with the fuel the maker recommends.
Does a new cylinder come with a piston?
It depends on the listing. A cylinder only is just the cylinder. A cylinder kit is sold with a piston and related parts, but contents vary. Read the title and description, and add a piston kit and gaskets if the listing does not include them.
Do I need new gaskets when I fit a new cylinder?
Yes. Use a new base gasket and a new head gasket or the sealing parts for your engine. Old gaskets compress and may leak. A top end gasket kit usually covers these, and you should clean the mating surfaces first.
How is cylinder bore size measured?
Bore is the inside diameter of the cylinder, measured in millimeters with a bore gauge or an inside micrometer. Your manual lists the standard bore and the wear limit. The piston has to match the cylinder, so size them together.
