NAMURA

Namura Top End Kits, Piston Kits and Cylinders for Dirt Bikes, ATVs and UTVs

A Namura title tells you the whole job in one line: the part number, what is in the box, the bore size, the compression ratio and the machine. We list about 525 Namura products, split between Motorcycle (about 280) and UTV | ATV (about 245). Roughly 415 are top end kits, 73 are piston kits alone and 25 are cylinders.

Namura's own About page says the company has operated since 2001, is based in Minnesota and makes pistons, rings, gaskets, connecting rods and bearings.

Reading the part number

NX- numbers are dirt bike and motorcycle kits (about 225), NA- numbers are ATV and UTV kits (about 235), FX- marks the forged kits (30) and CX- and CA- are the cylinders. After the number comes the bore, for example 66.35/STD or 76.95/+0.01, then the compression ratio and the make. About 195 titles are standard bore. The rest are oversize, mostly +0.50 (73 titles), +1.00 (54) and +1.50 (27), with small +0.01 and +0.02 steps also listed.

Dirt bike and motocross kits

Motorcycle kits live in Pistons, Rings & Piston Kits, and Honda, Yamaha, Kawasaki and Suzuki each appear on roughly 95 to 120 titles across the whole range. Two-strokes cover the Honda CR125R for '92-'99, the Kawasaki KX250 for '93-'03, the Suzuki RM250 for '03-'05 and the Yamaha YZ125 ceramic composite kit. Cylinder surface is written in the title: about 115 say Nikasil, 38 Ceramic and 33 Composite or SCEM.

Four-stroke riders can look at the forged kits: the Honda CRF250R and CRF250X for '04-'17, the Yamaha YZ250F for '19-'22, the Kawasaki KX250F for '06-'08 and the Husqvarna and KTM forged kit. The high compression forged kit for the '05-'15 YZ250F and WR250F is listed at 13.5:1. For small bikes there are the Honda CR85R and CR80R kit and the Kawasaki KX85 kit for '14-'20. About 44 KTM titles and 28 Husqvarna titles are in the mix too.

ATV and UTV kits

ATV and UTV piston kits are sorted by model line. Honda's Foreman kit for '98-'04 comes in standard, +0.25, +0.50 and larger steps. The Yamaha Raptor kit for '01-'05, the Yamaha Blaster OEM style kit and the Hyperdryve kit for Grizzly and Wolverine cover Yamaha. Polaris has about 65 titles, such as the Sportsman 500 kit and the Sportsman 570 kit. Kawasaki and Suzuki share the LT-Z400 and DR-Z400 Nikasil kit, and there are twin cylinder kits for the Can-Am Defender and the Kawasaki Mule 3010 and 4010.

Cylinders and bearings

Complete Cylinders holds the cylinder-only listings, such as the Honda CRF450R for '09-'16, the Yamaha YZ125 for '05-'22 and, in the ATV section, the Yamaha Raptor 700R and the Polaris 93 mm cylinder. Eight piston pin bearings, like the 14x18x17.2 size, are sold by dimension.

Matching the kit

Check the make, the model and the year range, then the bore. If you do not know your bore, measure the old piston before you pick STD or an oversize. Our fitment guide lists other checks.

Namura questions

Does a top end kit include the cylinder? Cylinder-only parts have their own listings marked CYLINDER ONLY, so read the full title and listing for what a kit contains.

How do I tell a piston kit from a top end kit? The title names it, either PISTON KIT or TOP END KIT, so compare the two listings for your machine.

Do ATV kits come in oversizes? Yes, many are listed in +0.25, +0.50 and +1.00 steps.

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