Hey! Even Tom Cruise…went “fon-fon!” with a GPZ900R (Ninja).
This one has a six-piston caliper, so…um…
So then,
the engine won’t start sometimes—scary when you’re out on the road, right? That’s what the customer said.
I thought it wouldn’t be a big deal, but it turned out to be a bit of a hassle.
First…
Lately, GPZ900Rs have been showing up more and more, so I bought a service manual. Kawasaki’s pricing is really reasonable—I’m grateful for that.
Having a manual versus not having one makes a huge difference. These days, not having a service manual is one of the reasons I turn down jobs.
But honestly, there are a lot of jobs where you really need a service manual—especially electrical work.
Donations welcome! (Rare bikes not needed.)Or maybe a permanent loan…
I’m waiting!
The new manual is so pristine that I’ve become the type to put a cover on it.
The size is a bit odd, so I had to hunt for a cover. Of course, I’m also looking at manuals and parts lists from other makers.
I’ll introduce those sometime. (Demand is pretty low.)
The manual paper is thin, so it creases easily—you’ve got to be careful from the start. Just like keeping your mind fresh and clean, I’m going to keep that same spirit going.
Now let me get to the main issue.
Kawasaki’s old bikes have this junction box—
it routes everything through individual relays, and honestly…it makes no sense. It seems like a waste of space.
They built it well, but historically it’s been phased out anyway.
So the symptom was:
when you press the starter button, this relay in diagram C makes a “jiii” sound or goes silent.
Sometimes it malfunctions intermittently, and depending on timing, the starter relay activates and the starter motor spins—that was the symptom.
Since relays B, C, and D have the same part number and capacity, I swapped them around and it worked better, so I figured it was one of those.
Just to be sure, I put a multimeter on the right switch’s starter button and did a continuity check—it showed continuity 100 out of 100 times.
But it still made that “jiii” sound occasionally, so…hmm?
I thought maybe it was the battery voltage, so I tested it with a booster, but there was no change. That’s when I figured it wasn’t the relay.
Could it be the right switch? I took it apart, cleaned it, and applied contact cleaner, and…
it was fixed. Turns out there was a slight contact issue that wasn’t letting the relay work properly.
Then I thought about ordering a new switch, but…
the GPZ900R right switch is discontinued, so I’m going with a swap strategy.
This is where the manual really comes in handy. I check the wiring diagram for the switch layout and wire colors, then find a compatible switch from a similar model—sounds simple, but it’s actually tedious.
What I’m looking for:
• Left switch with cable-operated choke
• Connector terminal shape identical so I can just swap it in
• Same number of poles
• Reasonably priced
So I found one—it’s from a ZRX1100 and similar models.
46091-1672 Right switch
46091-1858 Left switch
I compared the wiring colors and layout of the GPZ900R and ZRX1100 according to the manual.
You might think that since the maker and colors are the same, it’ll be fine as-is, but some switches in the world have branches inside the handlebar switch or in the wiring.
You can’t forget Bridgestone’s spirit of “hit it and cross it.”
The left was almost a direct swap, and the right only needed two wires swapped.
And that’s how the left and right switches got replaced (*’ω’*)
I’m letting you know because I think a lot of people don’t realize this when they customize.
• If the symbols or text on the handlebar switch aren’t visible, it fails inspection. (Same goes for the main key.)
• Depending on the year (model approval year), if there’s a headlight ON/OFF function, it fails inspection.
If nobody notices, you might get away with it, but basically it’s a no-go, so be careful…
