1981 GSX1100 Katana Based Project

[Shin-Ken 1074]

The rear brake master cylinder didn't work when I tested it, but it was bought as a used part and the best thing is to rebuild it to know what you have. Ordered a kit for it and today is the day to see what is inside.

A bit of gunge and a stuck piston.

Master 3 by Max Mutarn, on Flickr


master 1 by Max Mutarn, on Flickr


Master 2 by Max Mutarn, on Flickr



Didn't want to damage the bore when trying to remove the stuck piston so made a plunger from a toothbrush that was the perfect size to fit inside the bore. Tapped the plunger a few times with a spanner and the piston started to free up and slowly worked its way out with help from the spring. Got lucky there, sometimes the corrosion damages the bore to the point the seals can't do what seals should do and the cylinder is a right-off.

Master 7 by Max Mutarn, on Flickr


Master 8 by Max Mutarn, on Flickr


Master 9 by Max Mutarn, on Flickr

[Shin-Ken 1074]

That "last job" is so vital. Got access to a dyno?

Yes, there are a few Dyno places just over an hour away.

[Rob S.]

...the last job is sorting out the carb jetting.

That "last job" is so vital. Got access to a dyno?

[Shin-Ken 1074]

On the mechanical side, the rear master cylinder and rear caliper overhaul is the third last job to be done, I have the master cylinder kit and the rear caliper kit should arrive next week. Second last job is adapting the GSX-R1100 R/H switchblock to the 1981 Kat harness and the last job is sorting out the carb jetting. Getting closer to ride time.

[Shin-Ken 1074]

Finally got around to trimming the hollow front axle today. Too long, too ugly and too heavy!


Front axle 1 by Max Mutarn, on Flickr


Front axle 2 by Max Mutarn, on Flickr


Front axle 3 by Max Mutarn, on Flickr


7 grams that isn't needed anymore.

Front axle 5 by Max Mutarn, on Flickr


Running tally = 184,444 grams.

[Shin-Ken 1074]

Fitted the front calipers today and bleed the system, wow the Nissin adjustable brake lever is so much better to use that the 1982 very basic OEM lever system.

Front caliper 1 by Max Mutarn, on Flickr


Adjust lever 1 by Max Mutarn, on Flickr


Adjust lever 2 by Max Mutarn, on Flickr

[Shin-Ken 1074]

Due to the holidays and such I had not visited the thread in several weeks, but I'm glad to see you came so close to your desired weight reduction. Maybe lay off the beers a bit and the total weight of bike+rider could still hit "minus 50kg" hahaha.
It's crazy when you think about it; this big bike now weighs less than my Honda CB-1!

Lay off the beer, oh no please no! After a hot day slaving away that first cold beer is a joy that is hard to beat!

[Diirk]

Due to the holidays and such I had not visited the thread in several weeks, but I'm glad to see you came so close to your desired weight reduction. Maybe lay off the beers a bit and the total weight of bike+rider could still hit "minus 50kg" hahaha.
It's crazy when you think about it; this big bike now weighs less than my Honda CB-1!

[Shin-Ken 1074]

Update for the tally, the new cables are 5 grams heavier than the old cables so running tally is now:

184,451 grams.

[Shin-Ken 1074]

Installed the new twin throttle cables and fitted the carbs today. Red rubber grease is your best friend when installing carbs with new boots, so much easier, just push straight on with no effort!


Carb 21 by Max Mutarn, on Flickr


Carb 22 by Max Mutarn, on Flickr
Carb 23 by Max Mutarn, on Flickr


Carb 24 by Max Mutarn, on Flickr

[Pewpew82]

Wanted to install the carbs and new cables today however, today was just too hot and humid to do anything. 40 Celsius and 95 % humidity is not my idea of fun these days so the carbs will have to wait. Aircon and cold beers were a much better option today.

Carbs A1 by Max Mutarn, on Flickr

I could go for 40F right about now. We had a couple days in the negatives last week here in Ohio

[Shin-Ken 1074]

Wanted to install the carbs and new cables today however, today was just too hot and humid to do anything. 40 Celsius and 95 % humidity is not my idea of fun these days so the carbs will have to wait. Aircon and cold beers were a much better option today.

Carbs A1 by Max Mutarn, on Flickr

[Shin-Ken 1074]

second that, i am in awe of the weight loss achieved (and the detailed documentation), and think anyone trying to achieve similar would be very happy to read through this thread. Added to my favorites early on.

Hi Rijko, glad to hear you think it has been a worthwhile project, thank you for your support.

Cheers.

[Rijko]

No problem, all the details have been listed here. Just follow the bouncing ball through the posts and you will be able to compile a list of parts and weights in your preferred order.

second that, i am in awe of the weight loss achieved (and the detailed documentation), and think anyone trying to achieve similar would be very happy to read through this thread. Added to my favorites early on.

[Shin-Ken 1074]

Used Red Rubber Grease for the slide pins and boots.


Caliper 11 by Max Mutarn, on Flickr


Caliper 13 by Max Mutarn, on Flickr


Used a pine rod to install the captive slide pin boot, makes it easy to install.

Caliper 14 by Max Mutarn, on Flickr

Caliper 15 by Max Mutarn, on Flickr


Slide pins ready to be installed.

Caliper 16a by Max Mutarn, on Flickr


Caliper 16b by Max Mutarn, on Flickr


One caliper done, rinse and repeat.

Caliper 16c by Max Mutarn, on Flickr


Caliper 17 by Max Mutarn, on Flickr