1981 GSX1100 Katana Based Project

[Shin-Ken 1074]

Stator, ignition, clutch, tappet and sprocket cases have been removed and being painted later. Cases will be installed with new gaskets when they are ready and some modifications are complete.

DW engine painted 1 by Max Mutarn, on Flickr

[Shin-Ken 1074]

DW engine painted 5 by Max Mutarn, on Flickr

[Shin-Ken 1074]

DW engine painted 3 by Max Mutarn, on Flickr

[Shin-Ken 1074]

DW engine painted 6 by Max Mutarn, on Flickr

[Shin-Ken 1074]

Sprocket case after stitch drilling and file work between each of the cast gussets.

DW sprocket case 1 by Max Mutarn, on Flickr

[Shin-Ken 1074]

DW sprocket case 2 by Max Mutarn, on Flickr

[Shin-Ken 1074]

OEM sprocket case

DW sprocket case OEM by Max Mutarn, on Flickr

[Shin-Ken 1074]

DW 180 modified sprocket case 486 grams lighter.

DW sprocket case 4 by Max Mutarn, on Flickr

[Shin-Ken 1074]

The EF stator case had a bit of road rash that needed some attention before painting, nothing serious, just not as tidy as it should be.

stator case 1 by Max Mutarn, on Flickr


stator case 2 by Max Mutarn, on Flickr

stator case 3 by Max Mutarn, on Flickr


stator case 6 by Max Mutarn, on Flickr


stator case 7 by Max Mutarn, on Flickr


stator case 11 by Max Mutarn, on Flickr

[Shin-Ken 1074]

Where I can I like to change the profile of a part to reduce weight rather than the usual path of making parts into Swiss Cheese. It isn't always possible but when it is it can be a very subtle way to reduce weight.

Have replaced the OEM SZ steel rear brake pedal with an 1983 SD aluminium pedal and reshaped it using a file and fitting a titanium bolt.

This pic shows two SD aluminium brake pedals, left pedal is stock and right one is after reshaping.


DW v OEM brake pedal by Max Mutarn, on Flickr

[Shin-Ken 1074]

OEM 1982 SZ steel brake pedal.

DW brake lever OEM by Max Mutarn, on Flickr

Modified OEM SD aluminium brake pedal.

DW ally brake pedal by Max Mutarn, on Flickr

[Shin-Ken 1074]

SZ OEM steel brake pivot.

OEM steel brake pivot by Max Mutarn, on Flickr


DW OEM brake pivot bored out 13mm.

DW hollow brake pivot by Max Mutarn, on Flickr

[Shin-Ken 1074]

At Last the tally moves. Tally = 96,299 grams.

DW rear brake 1 by Max Mutarn, on Flickr

[Shin-Ken 1074]

OEM steel engine rear bolt spacer. Tally = 96,299 grams.

OEM rear engine bolt spacer by Max Mutarn, on Flickr

DW ally engine rear bolt spacer.

DW ally engine rear bolt spacer by Max Mutarn, on Flickr

[Shin-Ken 1074]

OEM SZ triple tree can be lightened and this is weight from a high point on a bike so reducing weight here helps with lowering C of G. I had the engineering company that made the ally axle spacers also make an aluminium steering stem for the DW. After reshaping the top plate with my set of files and using titanium bolts there has been a healthy reduction in weight for the complete triple tree.

The numbers:

SZ OEM triple tree complete including bearings = 2,473 g.

DW mod triple tree complete including bearings = 1,851 g.

Total weight reduction of triple tree = 622 grams


Running tally = 98,150 grams.

SZ OEM top plate by Max Mutarn, on Flickr

DW by Max Mutarn, on Flickr

DW triple tree by Max Mutarn, on Flickr


DW aluminium stem by Max Mutarn, on Flickr