Author Topic: Mixed jet sizes?!  (Read 795 times)

Offline Bowf

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Mixed jet sizes?!
« on: July 01, 2023, 01:27:15 PM »
I've got my carbs off for cleaning, and notice the main jets are 130 for cylinders 1 & 4 and 125 for 2 & 3.

Is there any good reason for that?

It's a USA 2006 model, not California. Pilot jet sizes are 38 throughout.

Offline tynesidebob

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Re: Mixed jet sizes?!
« Reply #1 on: July 03, 2023, 01:20:25 PM »
That is common for Kawasakis.
Zzr1100 had the same.
They know more about engines than I do so I just accept it must be right.

Offline Bowf

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Re: Mixed jet sizes?!
« Reply #2 on: July 03, 2023, 02:35:36 PM »
Thanks, Bob. I've since read that on an inline four, cylinders 2 & 3 run hotter than 1 & 4. A bit like your soup is hotter in the middle of the bowl.

That totally makes sense, but I have seen conflicting views about whether 2 & 3 therefore need more fuel or less. Anyway, I'm going to downsize all jets and try a home-made version of Steve's 2-minute mod. I wanted to buy the kit, but he told me he doesn't ship to the UK.

As for the #38 pilot jets, all I can see on the forum is #35. A look at the spark plugs suggests the bike is running rich.



Offline Stasch

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Re: Mixed jet sizes?!
« Reply #3 on: July 04, 2023, 06:29:32 AM »
I don't think that's how it came OEM.

I've been inside a couple dozen sets of ZG1000 carbs including CA models.

They always had the same main jet sizes for all 4, 130 for CA and 125 for 49 staters.
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Offline George R. Young

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Re: Mixed jet sizes?!
« Reply #4 on: July 04, 2023, 07:07:49 AM »
. . . 130 for CA and 125 for 49 staters.
And that's what it says in the manual. Canadian ones got 125's also.
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