{"id":9445,"date":"2025-01-24T13:52:39","date_gmt":"2025-01-24T04:52:39","guid":{"rendered":"https:\/\/www.decoboco.info\/en\/?p=9445"},"modified":"2026-09-24T13:46:41","modified_gmt":"2026-09-24T04:46:41","slug":"is-the-kz900-really-quite-niche-overhauling-the-troublesome-mikuni-carb","status":"publish","type":"post","link":"https:\/\/www.decoboco.info\/en\/20250124\/everyday-events\/is-the-kz900-really-quite-niche-overhauling-the-troublesome-mikuni-carb","title":{"rendered":"Is the KZ900 really “quite niche”? The troublesome Mikuni carb used in Z-series STDs. Overhauling the VM26SS."},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

The more I look at it, the less I understand what’s original.
There are bent parts and scratched parts scattered throughout that can’t be used as-is… <\/p>\n\n\n\n

I happened to have a parts donor, so I’ll carefully examine both and consolidate them into one. <\/p>\n\n\n\t\t

\n\t\t\t\t\t\t\t
\n\t\t\t\t\t\n\t\t\t\t\t\t\"\"\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\n\t\t\t\t\t\tPAMS AS Uotani SP2 ver.PAMS (Single Plug) Full Power Kit Z750-1100 72-85 Z1\/Z2 KZ900 KZ1000A Z750FX Z1000MK2\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\n\t\t\t\t\t\t\t\t\t
\u6de1\u8def\u4e8c\u8f2a\u30ab\u30b9\u30bf\u30e0\u30d1\u30fc\u30c4\u30bb\u30f3\u30bf\u30fc<\/div>\n\t\t\t\t\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\u00a599,330\t\t\t\t\t\t\uff082024\/12\/17 22:51\u6642\u70b9 | \u697d\u5929\u5e02\u5834\u8abf\u3079\uff09<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tAmazon\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tRakuten\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tYahoo!\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\"\"\n\t\t\t\t\t\u30dd\u30c1\u30c3\u30d7<\/span>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\n\n<\/a>\n\n\n\n\n\n\n
<\/div>\n\n\n\n

When I checked the site again the other day, the manual wasn’t available. <\/h2>\n\n\n\n
\"\"<\/figure>\n\n\n\n

It’s all messy and the images are a bit sparse.
The linkage is set up a bit strangely,
and getting the carb synchronization and throttle valve position right was somewhat novel. <\/p>\n\n\n\n

I didn’t quite understand the logic, so I checked the service manual again,
but it’s pretty rough and I just have to proceed while understanding the structure. <\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

The idle screw engagement is really just barely there.

Taking into account the synchronization height and the balance of idle adjustment,
synchronization won’t hold \/ idle is too high \/ idle can’t be adjusted <\/strong>
and other issues could arise, so I need to be careful. <\/p>\n\n\n\n

<\/div>\n\n\n\n

The throttle valves are almost completely shot. <\/h2>\n\n\n\n
\"\"<\/figure>\n\n\n\n

Whether it was because I wanted to synchronize according to the manual or because the throttle valve damage was severe.
<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n

I check the height with the one that has the slit, so what happened??? <\/p>\n\n\n\n

<\/div>\n\n\n\n

Borrowing a throttle valve from the parts donor. <\/h2>\n\n\n\n
\"\"<\/figure>\n\n\n\n

I’m writing it pretty simply, but the throttle valve is corroded and won’t come out, <\/strong>

and on top of that the linkage bolt is seized and broken\u2014a truly godlike situation.
This Z-series VM carb leaves me with nothing but bad impressions…
I still have to check the VM on the Z1R, so I’m feeling heavy about it… <\/p>\n\n\n\n

<\/div>\n\n\n\n

For now it’s assembled and I checked the actual fuel level. <\/h2>\n\n\n\n
\"\"<\/figure>\n\n\n\n

I didn’t want to waste the float valve, so I just lapped it and reused it.
The fuel level height was fine, so I’m relieved. <\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

I started the engine and got the synchronization perfectly dialed in.

The idle is also stable and it’s in a really nice condition.
The full throttle stopper was engaging at a halfway point and wouldn’t open fully.
I adjusted that too, so now it should rev all the way to the red line on the tachometer. <\/p>\n\n\n\n

<\/div>\n\n\n\n


<\/p>\n\n\n\n

Old motorcycles are scary, scary\u2014caution is necessary. <\/h2>\n\n\n\n
\n
\n
\"\"<\/figure>\n<\/div>\n\n\n\n
\n
\"\"<\/figure>\n<\/div>\n<\/div>\n\n\n\n

The center stand stopper should be black, so I painted it with gun coat.
I installed it first thing in the morning and cracked it wide open while there was still time. <\/p>\n\n\n\n

And that’s how it’s complete! <\/p>\n\n\n\t\t

\n\t\t\t\t\t\t\t
\n\t\t\t\t\t\n\t\t\t\t\t\t\"\"\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\n\t\t\t\t\t\tGSX1100S GS1000 GSX-R1100J-N GPZ900R GSX-R750GR71 YB14L-A2 Compatible Gel-Type GL-PB14L-A2 Nano Gel Battery Acid-Filled and Charged ProSelect Battery\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\n\t\t\t\t\t\t\t\t\t
ProSelect<\/div>\n\t\t\t\t\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\u00a58,220\t\t\t\t\t\t\uff082026\/09\/20 10:33\u6642\u70b9 | Amazon\u8abf\u3079\uff09<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\"\"\n\t\t\t\t\t\t\t\u53e3\u30b3\u30df\u3092\u898b\u308b<\/span>\n\t\t\t\t\t\t<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tAmazon\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tRakuten\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tYahoo!\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\"\"\n\t\t\t\t\t\u30dd\u30c1\u30c3\u30d7<\/span>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\n\n\t\t
\n\t\t\t\t\t\t\t
\n\t\t\t\t\t\n\t\t\t\t\t\t\"\"\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\n\t\t\t\t\t\tPAMS AS Uotani SP2 ver.PAMS (Single Plug) Full Power Kit Z750-1100 72-85 Z1\/Z2 KZ900 KZ1000A Z750FX Z1000MK2\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\n\t\t\t\t\t\t\t\t\t
\u6de1\u8def\u4e8c\u8f2a\u30ab\u30b9\u30bf\u30e0\u30d1\u30fc\u30c4\u30bb\u30f3\u30bf\u30fc<\/div>\n\t\t\t\t\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\u00a599,330\t\t\t\t\t\t\uff082024\/12\/17 22:51\u6642\u70b9 | \u697d\u5929\u5e02\u5834\u8abf\u3079\uff09<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tAmazon\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tRakuten\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\tYahoo!\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\"\"\n\t\t\t\t\t\u30dd\u30c1\u30c3\u30d7<\/span>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\n\n