KZ900 Gasoline Leak Prevention | Replacing the “Troublesome” Tank Cap with PMC & Fitting Adjustment

A troublesome task! Replacing the fuel cap with press-fit pin fastening.
With older bikes, you never know what’s been done to them in the past.

The pins can deform and expand when struck, or become difficult to remove due to corrosion. There’s also a risk the base itself is rusted. Considering these risks, it’s safer not to hammer.
So I made a tool to remove it and extracted the pin.

Osaka Kakuda Kogyo KH-9B Hand Vise No.9B

I prefer reasonably priced tools that can be repurposed for other jobs.
After all, you don’t want something that’s only good for one specific task.

Don’t you think this would come in handy for welding too?
I spent hours imagining and searching…
Every time I wonder what I’m doing.

But having the right tools definitely makes work progress smoothly, so let’s keep investing in tools and equipment.

Time flows on… and I machined it.

Materials prepared: SCM 2.5φ pin and 15mm aluminum scrap.
Surprisingly simple construction.

This vise handle has a flexible structure,
so I chose one that won’t have grip issues from contact or other problems.

The pin would be better if it were a bit longer. *30mm would be ideal (this time it’s 20mm due to availability).
The aluminum block needs a relief area for the extracted pin to escape.

Using thicker POM board with helicoils might be even better.

By placing it on a flat surface like this and centering left and right, you can extract the pin.

First protection, second protection. Cutting corners doesn’t save much time anyway.

A towel alone isn’t enough.
I cut and positioned protection board so it’s safe even if it slips.
Now I can work with confidence.

The design keeps improving as I work.
I couldn’t push it all the way, so I ground down the bolt tip.

Rather than pulling all at once, I checked the feel every few millimeters and carefully gripped with pliers to successfully extract it.
I’m not sure if I’ll need this again, but now I’m confident.

As expected, one side was deformed, so pulling in the wrong direction could have caused damage.
First check, second check. The older the bike, the scarier it gets.

After removing, clean thoroughly. Then it won’t let you down… hopefully.

Since you won’t be removing this area again, keep it clean.
The pin hole is also rusted, so running a drill through it and stroking it will smooth it out.

Plan ahead considering the upcoming press-fit and cap operation.

Request to make it a single key.

At first glance, the PMC reproduction fuel cap looks the same.
It seemed like it would go smoothly, but…

The structure up to this point is the same, but the repro differs from here on.
It has a proper key cylinder.

The original has a structure where any key inserted will turn, and the cylinder diameter is different, so reusing it is impossible.
I thought about disabling the cylinder function, but the old key wouldn’t even fit…

I kept assembling and disassembling… it was somewhat disappointing.

Inside the cylinder are small springs like this, so it’s risky.
The plate inside the cylinder has numbers written on it.
The order is silver-gold-gold. 2-1-no number. The no-number is the stopper.

Also made a base for pin press-fitting.

The insertion side of this spring pin should be slightly easier to enter, and straightening the crush helps.
That way the head sits slightly recessed, making the work easier.

Finally, without hammering, I modified the tip and inserted it gradually for completion.
Zero-risk replacement was definitely achievable, so I’m satisfied (*´ω｀*)

Great, great!
The work continues.

The inspection was already completed~
Other work continues.