OEM Ref.# 447-11635-01-96. Fits: 650's 1974-84 If you want to replace or go back to the stock 650cc piston, this is what you need. Note: Piston rings are not included in kit Part #05-0013 $45.46 Set

Piston Ring Set - Stock/Standard Size (for 1 piston). OEM Ref.# 447-11610-00-00. Fits: TX/XS650's 74-84 (447 & 533 type engines) Note: 447 type Rings interchange with European 533 Rings but pistons do not. 447 rings do not interchange with original 256 rings used on 1970-73 models. If you want to go back to a stock 650cc piston, this is the ring set you will need. If you want to replace rings on an original stock size piston this is what you need. Part #05-0016 $25.20 Ea.

Piston Ring Set-1st. oversize-0.25mm. (for 1 Piston) OEM Ref.#447-11636-01. Fits: TX/XS650's 74-84 (447 & 533 type engines) Note: 447 type rings interchange with European 533 rings but pistons do not. 447 rings do not interchange with original 256 rings used on 1970-73 models. Part #05-0018 $25.25 Ea.

Piston 2nd. Oversize (0.50mm.) + Piston & Clips. OEM ref.#447-11636-02 Fits: 650's 1974-84  Note: Piston rings are not included in kit Part #05-0019 $45.46 Ea.

Piston Ring Set - 3rd. Oversize - 0.75mm. (for 1 Piston). OEM Ref.# 447-11610-30. Fits: TX/XS650's 74-84 (447 & 533 type engines) Note: 447 type rings interchange with European 533 rings but pistons do not. 447 rings do not interchange with the original 256 rings used on 1970-73 models. Part #05-0022 $20.20 Ea.

Big Bore cylinder and piston kit- The only complete bolt on big bore 750cc Big Bore Cylinder and Piston Kit The Only complete bolt-on Big Bore 750cc Cylinder and piston kit ever made for the XS650 Yamaha Modified limited production European Race Engine Cylinder Block has enlarged fins for improved cooling. The New Cylinder Block has longer fins matching the Head Fin Length. Kit Fits: 1974-84 447 Type Engines Kit Includes: 1. XS Performance Big Bore Race Cylinder Block with sleeves installed and finished to fit our 80mm. Forged Big Bore (750cc.) Pistons. Cylinder casting has larger cooling fins that extend out the same distance as the cylinder head fins for enhanced cooling. No modifications to engine cases needed. 2. Forged 80mm. 750cc Big Bore Piston kits(2) complete with Ring Sets, Piston Pins & Clips. Forged 447 type Pistons feature: 1. Valve pockets cut for large valves. 2. Mos2 treated piston skirts. 3. Oil channel for enhanced piston pin oiling. 4. 20mm. piston pins that are internally tapered to ends for weight reduction. 5. Lightweight 9:1 compression pistons. Assembly - Weight approx. 455 Grams. 6. Big Bore Cylinder Head Gasket & Base Gasket. Fitted with our XS Performance Camshaft, Dellorto Carbs, a free-flowing Exhaust and Iridium spark plugs will result in about 65 Rear wheel Horsepower or more and 50 foot-pounds of Torque. See Dyno Chart 1 Dyno. Note: Stock Cylinder bore size is usually about 75mm. Stock Piston size is around 74.945mm. and the Standard size piston has.945 marked on its top (the "74" is always  dropped). Standard original piston size varies slightly so the piston may also be marked .965 or otherwise. Standard bore clearance is 0.0020- 0.0022 in. ( 0.050- 0.055mm). Oversize pistons are marked in mm. A 1st.over piston is marked 0.25 which is equivalent to 10 thousandths of an inch . 2nd. OS is marked 0.50 etc. Top and 2nd. Ring End Gap (measured in cylinder) should be a minimum of 0.008" and Oil rings should have a minimum gap of 0.012". Part #05-0750 

			Replacement Piston Ring Set to fit XS Performance 81mm. Pistons ( XS# 05-0753 ) Set = Rings for one 81mm. (1st. over) piston. Part #05-0754 $29.80

Cylinder Sleeve for Big Bore (750cc.) 80mm. Pistons. Note: Stock cylinder sleeves must be removed and the cylinder block Must be bored to accept this larger sleeve and then the new sleeve must be bored to accept the new larger big bore pistons. Part #05-0757 $82.95