Honda CB350 K4 Close Ratio 6 Speed Gearbox

Full six speed close ratio gear set comprising both input and output shafts and all gears, selector drum with indexing block and works with the standard selector forks. Supplied fully assembled ready for installation.

All engagement dogs are undercut and have three dogs to promote positive and rapid engagement.

Due to the change in diameter of the gears, the kickstart mechanism will not work with this gearbox, therefore roller starters will be required to start up.

NOTE: A small modification is required to the standard selector forks, this is simply to clear the Nova gears when shifting. For instructions CLICK HERE

1st 17 – 34 2.000:1
} 25.0%
} 15.0%
} 12.74%
} 10.07%
} 7.1%
2nd 22 – 23 1.500:1
3rd 22 – 28 1.273:1
4th 27 – 30 1.111:1
5th 25 – 25 1.000:1
6th 28 – 26 0.929:1
Overall reduction 1st – 6th 53.6%

1st 2.353:1
} 30.5%
} 22.4%
} 18.4%
} 13.1%
2nd 1.636:1
3rd 1.269:1
4th 1.036:1
5th 0.900:1
Overall reduction 1st – 5th 61.8%

Honda CB350 K4 Close Ratio 6 Speed Gearbox

Price £1911.00

+VAT (if applicable) & Carriage.

Nova assembly: 51

Honda CB350 K4 Updated Selector Mechanism

This updated selector mechanism is designed to be used with Nova 6 speed gearboxes only, and replaces the MK3 Honda mechanism.

It will not work with the earlier MK1 & MK2 mechanisms.  Please contact us or send us a photo of your mechanism if you are unsure of compatibility.

Kit Includes the following components.

  • Retaining Washer
  • M6 x 30 Countersunk BoltIndexer Plate
  • Indexer Plate Rivet
  • Indexer Plate Spring
  • Indexing Roller
  • Indexing Roller Arm
  • Indexing Roller Rivet

A revised pin block and hook arm are available on request at an additional cost.

NOTE: A small modification is required to the standard selector forks, this is simply to clear the Nova gears when shifting. For instructions CLICK HERE

1st 17 – 34 2.000:1
} 25.0%
} 15.0%
} 12.74%
} 10.07%
} 7.1%
2nd 22 – 23 1.500:1
3rd 22 – 28 1.273:1
4th 27 – 30 1.111:1
5th 25 – 25 1.000:1
6th 28 – 26 0.929:1
Overall reduction 1st – 6th 53.6%

1st 2.353:1
} 30.5%
} 22.4%
} 18.4%
} 13.1%
2nd 1.636:1
3rd 1.269:1
4th 1.036:1
5th 0.900:1
Overall reduction 1st – 5th 61.8%

Honda CB350 K4 Updated Selector Mechanism

Price £61.00

+VAT (if applicable) & Carriage.

Nova assembly: 54