• Out of stock
    Piston 4th. Oversize (1.00mm.) + Piston Pin & Clips. OEM Ref.# 447-11638-01. Fits: 650's 1974-84 Note: Piston rings are not included in kit Part #05-0023 $45.46 Ea.
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    Big bore (81mm.) Piston kit

    Original price was: $83.95.Current price is: $69.95.
    Big Bore (81mm.) 1st. Oversize Piston Kit - for 750 Engine Kit for Yamaha XS650's. One Forged Piston, 1 Ring set, 1 piston Pin, 1 set of rings for one piston. Features: Valve pockets cut for large valves, 2. Mos2 treated piston skirts. 3. Oil chanel for enhanced pin oiling. 3. 20mm.piston pins that are internally tapered for lighter weight. Piston weight approx 455 Grams. One Big Bore needs two Kits of Piston . Part #05-0753 $83.95 /Kit 
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    Big bore (80mm.) Piston kit

    Original price was: $83.95.Current price is: $74.95.
    Big Bore (80mm.) Piston Kit - for 750 Engine Kit for Yamaha XS650's. One Forged Piston, 1 Ring set, 1 piston Pin, 1 set of rings for one piston. Features: Valve pockets cut for large valves, 2. Mos2 treated piston skirts. 3. Oil chanel for enhanced pin oiling. 3. 20mm.piston pins that are internally tapered for lighter weight. Piston weight approx 455 Grams. Fits : 1974-84 Part #05-0752 $83.95
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    Pistons and piston Ring Set – Stock/Standard Size. Fits: TX/XS650’s 74-84

    Original price was: $129.00.Current price is: $79.95.
    Piston - Stock/Standard Size + piston pin & clips ( Kit Contains : 2 Cast pistons , 2  piston pins & clips  05-0013  + 2 sets of Piston Ring 05-0016) Piston Ring Set - Stock/Standard Size (for 1 piston) Fits: TX/XS650's 74-84 ( 447 & 533 type engines - 1974-84 ). OEM Ref.# 447-11610-00-00 Fits: 650's 1974-84 OEM Ref.# 447-11635-01-96 If you want to replace or go back to the stock 650cc piston, this is what you need. # 05-0013 Set
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    Piston 1st. Oversize Kit

    Original price was: $129.95.Current price is: $79.95.
    Piston 1st. Oversize ( 0.25mm.) 05-0017  + piston pin & clips - Fits: 650's 1974-84 OEM Ref.# 447-11635-01. Piston Ring Set ( 05-0018) - 1st. Oversize - 0.25mm. ( for 1 piston ) Fits: TX/XS650's 74-84 (447 & 533 type engines - 1974-84). OEM Ref.# 447-11636-01. 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. Kit includes: 2 Pistons 1st. Oversize ( 0.25mm.) 05-0017 + 2 pins + clips + Rings (2 set  05-0018 )
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    447 Piston – 2nd. oversize ( .50mm.) Kit

    Original price was: $129.95.Current price is: $79.95.
    Piston 2nd. Oversize ( 0.50mm.) + piston pin & clips - Fits: 650's 1974-84 OEM Ref.# 447-11636-01. Piston Ring Set - 2nd. Oversize - 0.50mm. ( for 1 piston ) Fits: TX/XS650's 74-84 ( 447 & 533 type engines - 1974-84 ). OEM Ref.# 447-11610-20. 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. Kit includes: 2 ( 2nd over size pistons  05-0019) + 2 pins + Clips + 2 Rings set ( 05-0020)
  • Out of stock
    Stock 650cc. Cylinder Sleeve. Replaces damaged or worn out original sleeve so engine can go back to stock piston size (approx. 74.94mm. or 2.95" ) or any of it's oversizes. ID, OD, length and thickness dimensions are the same as original. Fits: All 1970-84 stock cylinder blocks. Note: After installation of sleeve into your cylinder, sleeve must be sized (bored/honed) to accept the pistons you are using. This operation should be performed by a competent professional machine shop Part #05-0758 $82.95
  • Out of stock
    New XS Performance Street Cam - 447 Type - But with 1970 XS1 Grind by Web Cam ( Includes a $50.00 refundable core charge ). Part #05-0079 $249.00 Ea.
  • Big Bore Cylinder Block with cylinder sleeves installed and finished to fit 80mm. (79.94mm. (750cc. ) Note: Block only No pistons included. This cylinder is for those that have their own ( Hi-Compression ) pistons. Fits: 74-84 447/533 type engines. Cylinder casting has larger fins that extend out the same distance as the head fins for enhanced cooling. No modification needed to engine cases. Part#05-0759 $300.00
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    447 Big Bore kit-80mm.(750cc)

    Original price was: $499.95.Current price is: $450.00.
    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 

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