1981 GSX1100 Katana Based Project

[Rob S.]

You've told your wife this all just an investment, right?

[Lorenzo]

Less Is more...

[Shin-Ken 1074]

You've told your wife this all just an investment, right?

Lucky for me I don't have to try and slide the build through on a paper thin reason like "an investment". My wife is very much Kat aware and is pretty clued up on Kats their parts and prices, we ride and hang out with Kat people and talk Kats most days. At times she has suggested buying parts that she knows are becoming difficult to find to future-proof the Kat, what a wonderful wife!

[Shin-Ken 1074]

OEM horn painted silver in its new location. Much easier to access the tappet cover now and the horn is a bit louder facing towards the front instead of the OEM position facing down towards the tappet cover.

horna1 by Max Mutarn, on Flickr

[Shin-Ken 1074]

There are still a few things to sort out like overhauling the calipers and master cylinders and tuning the carbs however, yesterday was spent going through the wiring system. An aftermarket main harness, SZ Kat electrics - coils, igniter, switchblocks, clocks and indicators and a 1985 GSX 1135 EF engine. Carbs had been sitting for a year on the shelf with an unknown history and in full knowledge they will need to be overhauled but the goal yesterday was to see if the engine would fire-up and the electrics would work.

Success, the engine fired and ran after a few seconds on the starter button, sort of. Only cylinder 1 and 4 doing their job, 2 and 3 header pipes cold, gave 2 and 3 intakes a squirt of fuel and they fired up.

O.K. no fuel getting through 2 and 3, no drama.Carbs off in abound 30 seconds, no airbox makes it so easy to work on the carbs. Sure enough 2 and 3 were gummed up so a quick clean and reinstall. Fired up and ran on all cylinders so with that a major step forward, a working engine. Next job is to strip down and service the carbs and after that to sort out jetting. Right now it is still fitted with the 750 jets ex-factory.

Tested horn, lights, indicators, instrument lights, brake lights and went well except for the rear tail light. Tail light not working, brake light circuit is fine but no tail light working. Will go through the wiring again to find the problem however, I am very happy with results.

My mate the "Wizard" sorting out the electrics in his shed. The "Dark Art" of electrics is beyond my mental capacity so I am very fortunate to have help from a mate who knows how to wrangle those pesky little elec-trickery goblins!

Electrics1 by Max Mutarn, on Flickr

[Rob S.]

Lucky for me I don't have to try and slide the build through on a paper thin reason like "an investment". My wife is very much Kat aware and is pretty clued up on Kats their parts and prices, we ride and hang out with Kat people and talk Kats most days. At times she has suggested buying parts that she knows are becoming difficult to find to future-proof the Kat, what a wonderful wife!

Wow! She got a sister (preferably in the northern hemisphere)?

[Shin-Ken 1074]

Wow! She got a sister (preferably in the northern hemisphere)?

You are not the first one to ask that question for some reason? Same answer though, no sister.

[Shin-Ken 1074]

When I mentioned we hang out with Kat riders and talk Kats, this is a BBQ at a mates place to give you an idea of what it is like when some local Kats gather around the BBQ for a chat.

Sat BBQ by Max Mutarn, on Flickr

Sat BBQ 2 by Max Mutarn, on Flickr

[Rob S.]

Mostly 1100cc, or varied sizes?

On this part of the planet, 1100 Katanas are few and far between.

[Shin-Ken 1074]

Mostly 1100cc, or varied sizes?

On this part of the planet, 1100 Katanas are few and far between.

On the day there was three 750cc, two 1000cc, five 1166cc, two 1230cc and the other seven were stock 1100cc. We have 27 Kats in our regular riding group in the local area however, there are another 43 Kats registered in the area that have chosen to do their own thing however, sometimes we do meet up by chance on rides, bike shows and swap meets.

We also meet up with some Kat friends from NSW (the State on the Southern border of our State - QLD) each year for a weekend ride that is a round trip of about 1,200 km.

Kat Weekend by Max Mutarn, on Flickr

[steve murdoch]

27 Kats in your regular group is incredible.
Don't think i seen that many in total.

[Shin-Ken 1074]

27 Kats in your regular group is incredible.
Don't think i seen that many in total.

We have never managed to get all 27 Kats together at the one time, came close a few times but no cigar!

[Shin-Ken 1074]

Now that all four cylinders are firing the first of the teething problems has arrived. Idles on 2,200 revs with the idle adjustment backed off all the way. Not having an airbox fitted I can see the throttle stop is about 13mm from idle adjuster. Throttle cable is at maximum adjustment so removed the throttle tube for a look and compare it with the OEM throttle tube from another Kat. Bingo, different diameter where the throttle cable sits so all I had to do was rat through the spares box and find a tube to suit.

tube 1 by Max Mutarn, on Flickr


tube 3 by Max Mutarn, on Flickr


tube 4 by Max Mutarn, on Flickr


tube 5 by Max Mutarn, on Flickr


tube 2 by Max Mutarn, on Flickr

[Shin-Ken 1074]

Swapped the throttle tube and checked the throttle stop/idle gap, about 8mm, hhmmm the new cable is still short and putting tension on the carbs spindle. With no adjustment left for the throttle cable I decided to sacrifice a damaged throttle tube by cutting the stop shorter to allow more cable through the system.

tube 6 by Max Mutarn, on Flickr


Lowered the gap about 3 mm but still to high and idling at 1600 revs. I wouldn't trust the cut throttle tube even if it did lower the revs to the correct idle. So for now the two options to fix the problem are:

1) a longer throttle cable,

2) swap or modify the carb throttle cable bracket.

Will check the parts bin to see if there is an 1135 EF throttle cable lurking about and try that first.

[Shin-Ken 1074]

No joy finding an 1135 EF cable in the spares bin. There is little to no space available to modify the carb throttle bracket which is my preferred option as then stock throttle cables can be used. Will have to spend some time working this one out.

Where the throttle should be.

stop 1 by Max Mutarn, on Flickr

To gain a few mm positioned both lock nuts below the bracket and with cable at full adjustment top and bottom the cable is in tension and holding up the throttle stop.

stop 3 by Max Mutarn, on Flickr

stop 2 by Max Mutarn, on Flickr