Oil-cooled Katana Inazuma 1200 | GSX400S OEM Seat Adaptation & Installation Log

My Inazuma 1200 started out stock, and I had planned to transform it into an oil-cooled Katana,
but the condition was so good that cutting it up seemed wasteful.

Meanwhile, I’d been gradually collecting parts for the oil-cooled Katana conversion before the move.
And I’d been searching for an Inazuma 1200 frame for ages.
Ideally, I wanted something cheap and pristine without modifications, but they’re hard to find.

Then recently, I found an Inazuma 1200 for 200,000 yen—surprisingly affordable—and I was thrilled.
But then… I realized it came without paperwork. No wonder it was so cheap.
Well, at this age, getting the documentation sorted isn’t too difficult, hopefully.
Anyway, please bear with me as I work through this.

I happen to have an Inazuma 1200 Katana in progress, so let me check on it real quick. Hehe.

【DAYTONA×SANCTUARY RED EAGLE】 RCM Concept Cozy Seat

【DAYTONA×SANCTUARY RED EAGLE】 RCM Concept Cozy Seat (COZY Seat)

I had this ready ahead of time (*´ω｀*)
It looks sharp right out of the box. As expected, though… it’s long.
The tail sticks out quite a bit, and the proportions look off.

Comparison:
RCM Concept Cozy Seat / Unicorn Inazuma 1200 Katana.
The Unicorn Inazuma 1200 Katana uses a stock seat that’s been cut and paired with an original tail cowl.

Here’s the problem. Shortening the seat isn’t an issue, but…
when you shorten it,
the four GSX1100S tail cowl mounting points interfere with the seat base.
If I could use the GSX1100S tail cowl, I wouldn’t have delivery headaches down the road.
I really want to use it… because it’s dry carbon.

But shortening and clearing four mounting points sounds tedious, doesn’t it?
I basically like to keep a spare seat anyway, so doing the same mods twice is a pain.
Is there any other way…? Hey, Gemini, help me out here.

400 tank with 1100 seat. 400 with 1100 tail cowl.

After some research,
I found people doing GSX400S-to-1100-style customs, so I’m going to check those out.

In other words…
the GSX400S seat might align with the GSX1100S tail cowl line? I’m guessing.

What’s the difference between a GSX250S and GSX400S seat?

At first glance, they look identical and I can’t tell them apart.
You have to research carefully because sellers might mix them up too.

The GSX400S has a stopper-like base on the rounded section.
Since image scale and angles vary, I need to identify a definitive difference.

I bought it on Mercari yesterday and it arrived today! How convenient.
The listing title even said (250), so I did my homework.

So I lined them up.
From left to right:
GSX400S / Unicorn Inazuma Katana (1100 shortened) / GSX1100S RCM Concept Cozy Seat (1100 length)

Length and width look good, but… the front height on the GSX400S is lower…
to be continued.