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Discussion Starter · #1 ·
First of all thanks for an excellent resource for Kawasaki info. I own a '79 KZ1000 ST that I've had since '81 and still love! It's by far my longest relationship! The bike is pretty much stock but recently I put a Vance and Hines 4 into 1 on it. At speeds under about 100 KPH the bike runs fine but at higher speeds it will lose power for a few seconds and then clear up. My guess is that at higher rpm's the carbs can't keep up with the free flowing pipe. Another strange thing is that in gusty headwinds this condition is much worse and the bike runs quite poorly. Most of what I've read on rejetting says that it's a trial and error process. This is a pretty common bike/pipe combo and I'm sure someone has done the homework and hit the jetting right on. This is the info I'd like to find.
Also after a ride I'm getting a pretty strong gas smell so I think the carbs need new gaskets and are leaking a bit. I'd like to keep the stock airbox but if I rejet will also replace the stock filter with a K & N to free up air flow on both ends.

Any help will be appreciated.

Roger
 

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Typically a 4-1 on those bikes (with a K&N air filter) will warrant going up 3 or 4 sizes on main jet. Stock your bike would have 107.5 main jets and 15 pilot jet.

You want to change the pilot jets to 17.5.
Main jets to 115 or 117.5

If your bike is a Canadian spec model, then the slide needles in the carbs will have multiple clip settings. You will want to raise the needle 1 clip notch.
 

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Discussion Starter · #3 ·
Thanks very much Jeff. That's just what I was looking for. This will be a good winter project and I'm sure I can find gasket kits to restore the sealing on these carbs. Looking forward to spring to see the effects of this rejetting.

Cheers

Roger
 
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