The GSX1400, which had a surprisingly long production run (2001–2008), is already 12–19 years old now?
That’s a bit sobering.
We all age one year at a time, every year. It hits you when you think about it.
Anyway, at some point the owner noticed it would stutter and run rough when stuck in traffic or riding around town.
When revving it or holding higher RPMs, it still runs okay, apparently.
I wonder what’s going on.
Here’s the general flow.
Above 3000 RPM it was generating close to 14 volts, but around idle it was only putting out just over 12 volts—that was the problem.
The battery voltage was gradually dropping, which was causing the bike to lose power.
With fuel-injected bikes, I think it’s good practice to suspect the battery first, then work through other diagnostics from there.
We can’t just swap parts willy-nilly, so we’ll do a careful step-by-step check.
In a situation like this, it’s actually kind of easy—anyone can see it’s “no good.”
That’s when you can breathe a sigh of relief.
When “the looks are fine” or “the logic doesn’t make sense,” that’s when things get nerve-wracking.
Basically, there’s no such thing as “gremlins,” but there are cases in the world where the reasoning is thin.
So in a way, it might be tough but also kind of fun?
When the stator coil goes bad, it’s better to replace the regulator at the same time.
After the swap, the voltage came back strong.
Let’s clean the caliper and check the piston operation. Everything looks good—no issues.
We replaced the brake fluid with CCI Golden Cruiser DOT4.
Let’s degrease and clean the brake discs while we’re at it.
We’ll check the operation and apply lubrication from the outside.
The lubricant we’re using is I ♥ Bell Hammer (red)
We’re sticking with this one product for now!
Let’s apply rust protection and lubrication to the fork. The stopper ring had a bit of rust on it, so we applied rust-preventive oil on top.
We spent about half a day charging the battery.
It might have been right on the edge. The good news is the stuttering is fixed.
