®     Vintage Japanese piston to cylinder clearances

CB125 Single (pg 16)

CB175 Twin (pg 29)

CB350 Twin (pg 40)

CB350F SOHC Four (pg 76)

CB400F SOHC Four (pg 106)

Piston 55.97~55.99

Piston 51.96~51.98

Piston 63.97~63.99

Piston 46.47~46.99

Piston 50.97~50.99

Cylinder 56.00~56.01

Cylinder 52.00~52.01

Cylinder 64.01~64.02

Cylinder 47.00~47.01

Cylinder 51.00~51.01

Clearance 0.01~0.04

Clearance 0.02~0.05

Clearance 0.02~0.05

Clearance 0.01~0.04

Clearance 0.01~0.04

Clearance inches 0.00039~0.0016

Clearance inches 0.0008~0.0019

Clearance inches 0.0008~0.0019

Clear inches 0.0004~0.0015

Clear inches 0.0004~0.0015

Clearance average 0.0010

Clearance average 0.0014

Clearance average 0.0014

Clearance average 0.0009

Clearance average 0.0009

Clearance given NA

Clearance given NA

Clearance given NA

Clearance given NA

Clearance given NA

Clearance service limit 0.01181

Clearance service limit NA

Clearance service limit 0.00781

Clearance svc limit 0.00981

Clearance svc limit 0.00981

Ring end gap top 0.0059~0.0138

Ring end gap top NA

Ring end gap top NA

Ring end gap top 0.004~0.012

Ring end gap top 0.0059~0.0138

Ring end gap 2nd 0.0059~0.0138

Ring end gap 2nd NA

Ring end gap 2nd NA

Ring end gap 2nd 0.004~0.012

Ring end gap 2nd 0.0059~0.0138

Ring end gap oil 0.0059~0.0158

Ring end gap all 0.006~0.016

Ring end gap all 0.008~0.016

Ring end gap oil 0.010~0.0352

Ring end gap oil 0.0079~0.0197

End gap svc limit top NA

End gap svc limit top NA

End gap svc limit top NA

End gap svc limit top 0.0276

End gap svc limit top 0.0276

End gap svc limit 2nd NA

End gap svc limit 2nd NA

End gap svc limit 2nd NA

End gap svc limit 2nd 0.0276

End gap svc limit 2nd 0.0276

End gap svc limit all 0.0197

End gap svc limit all 0.0315"

End gap svc limit all 0.0315"

End gap svc limit oil 0.0276

Ring end gap svc limit all 0.035


CB500 SOHC Four (pg 139)

CB550 SOHC Four (pg 141)

CB750 SOHC Four (pg 23)

CB750 DOHC Four (pg 7-1)

CB900 DOHC Four (pg 7-1)

Piston 55.97~55.99

Piston 58.47~58.49

Piston 60.965~60.985

Piston 61.95~61.98

Piston 64.46~64.49

Cylinder 56.00~56.01

Cylinder 58.50~58.51

Cylinder 61.01~61.02

Cylinder NA

Cylinder 64.50~64.51

Clearance 0.01~0.04

Clearance 0.01~0.04

Clearance 0.025~0.055

Clearance see 900 spec

Clearance 0.01~0.05

Clear inches 0.0004~0.0015

Clear inches 0.0004~0.0015

Clear inches 0.001~0.002

Clear inches see 900 spec

Clear inches 0.0004~0.0019

Clearance average 0.0009

Clearance average 0.0009

Clearance average 0.0015

Clearance average see 900 spec

Clearance average 0.0012

Clearance given NA

Clearance given NA

Clearance given NA

Clearance given NA

Clearance given 0.0004~0.0020

Clearance svc limit 0.00981

Clearance svc limit 0.00981

Clearance svc limit 0.00981

Clearance svc limit 0.004

Clearance svc limit 0.004

Ring end gap top 0.005~0.013

Ring end gap top 0.005~0.013

Ring end gap top 0.007~0.016

Ring end gap top 0.004~0.012

Ring end gap top 0.006~0.012

Ring end gap 2nd 0.005~0.013

Ring end gap 2nd 0.005~0.013

Ring end gap 2nd 0.007~0.016

Ring end gap 2nd 0.004~0.012

Ring end gap 2nd 0.006~0.012

Ring end gap oil 0.010~0.0352

Ring end gap oil 0.010~0.035

Ring end gap oil 0.010~0.0352

Ring end gap oil 0.012~0.035

Ring end gap oil 0.012~0.035

End gap svc limit top NA

End gap svc limit top 0.027

End gap svc limit top NA

End gap svc limit top 0.020

End gap svc limit top 0.020

End gap svc limit 2nd NA

End gap svc limit 2nd 0.027

End gap svc limit 2nd NA

End gap svc limit 2nd 0.020

End gap svc limit 2nd 0.020

Ring end gap svc limit all 0.027

End gap svc limit oil 0.043

Ring end gap svc limit all 0.028

End gap svc limit oil 0.043

End gap svc limit oil 0.040


CB1100 DOHC Four (pg 10-1)

CBX1000 (79~82 pg 7-1)

VF750C/S 82 (pgs 12-1, 12-5, 25-22)

GL1000 (pg 6-2)

CBR600 F4 (pg 1-8)

Piston 69.970~69.980

Piston 64.47~64.49

Piston 69.960~69.990

Piston 71.945~71.970

Piston 66.965~66.985

Cylinder NA

Cylinder NA

Cylinder NA

Cylinder 72.000~72.150

Cylinder 67.000~67.015

Clearance see 900 spec

Clearance see 900 spec

Clearance NA

Clearance 0.030~0.105

Clearance 0.015~0.050

Clearance inches NA see 900 spec

Clearance inches NA see 900 spec

Clearance inches NA

Clearance inches 0.001~0.004

Clearance inches 0.0006~0.0019

Clearance average see 900 spec

Clearance average see 900 spec

Clearance average 0.0012

Clearance average 0.0025

Clearancce average 0.0013

Clearance given NA

Clearance given NA

Clearance given 0.0004~0.00202

Clearance given 0.0012~0.0027

Clearance given 0.0006~0.0020

Clearance svc limit 0.0039

Clearance svc limit 0.004

Clearance svc limit 0.0042

Clearance svc limit 0.006

Clearance service limit 0.002

Ring end gap top 0.0059~0.0138

Ring end gap top 0.006~0.012

Ring end gap top 0.004~0.012

Ring end gap top 0.010~0.016

Ring end gap top 0.004~0.008

Ring end gap 2nd 0.0059~0.0139

Ring end gap 2nd 0.006~0.012

Ring end gap 2nd 0.004~0.012

Ring end gap 2nd 0.010~0.016

Ring end gap 2nd 0.007~0.012

Ring end gap oil 0.018~0.035

Ring end gap oil 0.012~0.035

Ring end gap oil 0.012~0.035

Ring end gap oil 0.008~0.035

Ring end gap oil 0.010~0.030

End gap svc limit top 0.020

End gap svc limit top 0.020

End gap svc limit top 0.020

End gap svc limit top 0.027

End gap svc limit top 0.020

End gap svc limit 2nd 0.020

End gap svc limit 2nd 0.020

End gap svc limit 2nd 0.020

End gap svc limit 2nd 0.027

End gap svc limit 2nd 0.020

End gap svc limit oil 0.043

End gap svc limit oil 0.040

End gap svc limit oil 0.040

End gap svc limit oil 0.043

End gap svc limit oil 0.040

First three measurements only metric, the rest are Imperial

1 Incredible!

2 Corrected from obvious typo

© Mike Nixon, The Motorcycle Project


See also:
Cylinders done right
Valve Jobs Done Right
Cylinder Head Porting

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© 1996-2015 Mike Nixon