Maintenance finished, so I took it for a test ride and… something’s not quite right.
It’s running rough… I had noticed something a bit off before, but not like this.
Cylinder #3 is running badly, so I tried draining the carburetor first, but…
No luck at all.
There’s no point in dragging this out, so I removed the carburetors.
With each additional job, the heat is on—(ΦωΦ)—you know? These are all definitely vintage bikes now.
There was serious rust everywhere, max level. The bottom of the tank too, of course.
We’d like to fully disassemble and rebuild the four carburetors here, but the cost is substantial.
After thinking through the timeline and other factors, we’re doing a soft overhaul. (We don’t normally do this.)
This is what a carburetor overhaul typically looks like these days.
Ah, it’s been a while since I’ve done this… it’s both easy and tedious at the same time.
I’m not really a fan of dirty things by nature. (I think everyone feels the same way?)
When assembling, let’s go with that fresh new feeling—or rather, that fresh new fit.
Wow… it was originally milky white but has turned brown.
Time is a great thing.
The float valve has gotten super expensive, so BST might not be able to extend its life much longer.
13370-46E10 ¥6,300 before tax—I wish it was around ¥3,000.
People ask about aftermarket kits, but I bought one with my own money a while back and tested it. (I’ll keep the product name secret.)
The result was the same as old overseas stuff—the world isn’t that kind. When I installed it on the overhauled carburetor, the feeling was really weird, and when I switched back to the original inner, it ran perfectly!
I don’t think it’s possible for the price to be far below what major Japanese carburetor makers like Keihin and Mikuni produce at global sales volumes.
We lap the float valve and reuse it. It’s surprisingly effective.
The carburetor overhaul for Seiyoshi happened to have the OEM parts in stock, so we’re finishing it up today.
My feeling is to do it while it’s still warm and while the sky is still clear!
The hose is ordered from Yoshimura 877-260-1207, fits the 8mm inner diameter size.
This is basically my go-to 8mm fuel hose! It has good wall thickness, doesn’t collapse easily, and doesn’t harden too quickly (though it does harden over time).
The fuel level was a bit high on all four cylinders.
Honestly, you’re not always riding on perfectly straight roads, so… whatever.
But if you set the standard right, you reduce the guesswork when something feels off—like wondering if it’s the carburetor.
All right, done! Let’s get it assembled and take it for a test ride while the weather’s nice (*^-^*)
Oh, the throttle cable (carburetor side) was about to break…
A blessing in disguise. Maybe there really is a god…
And the OEM throttle cable is super expensive.
58300-27E00
58300-27E10 each ¥6,300 before tax. It might be better to go with an aftermarket throttle holder…
This time I went with an Arcan Hands cable (‘ω’)ノ
So that’s on hold for now. The tank too.
