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KZ400 Idle issues. I'm stumped.
- Nessism
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Spraying crap around the carbs is a poor test for vacuum leaks. Only gross leaks can be detected this way. A creeping idle when warm is a sure sign of lean running, and air leaks are the prime suspect.
I'd try opening up the pilot screws to at least 3 turns and vacuum syncing the carbs as the next step. After you restore the stock jets that is. While the carbs are off you might want to spray carb cleaner through the pilot circuit and confirm the passage is open all the way to inside the carb throat too.
Lastly, make sure your airbox is installed, filter installed, and everything is 100% sealed. Any air leaks in the system can cause lean running.
Good luck
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- DoctoRot
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The more i thought about it the more is seemed like an air leak to me, so i pulled the carbs and found the tiniest hole in the diaphragm. This very well may be the culprit. I sure didn't see it the first time around, but as i let the bike idle more, the problem seemed to get worse, so perhaps it was getting bigger. The good news is there is a company making reproduction diaphragms out there so i have ordered those.
jbmindustries.com/Keihin_diaphragm.html
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- Z650Spirit
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Pablo.
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- DoctoRot
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- DoctoRot
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suggestions?
BTW i carefully inspected the manifold boots and they don't appear to have any cracks and are quite supple still. I took them off and put a very fine coating of 1194 on the mating surface to make sure there was no leak. THe carb boots seem to have a good seal but they are kinda hard. The airbox and stock filter is in there properly.
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- Copbike1000
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I still had the issue of the bike running on two cylinders until you rolled the throttle to higher revs. I ended replacing the pilot jets and all is good.
1994 Kawasaki KZ1000P, Rancho Cordova, Ca
www.kzrider.com/forum/11-projects/598384...-project-bike#674472
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- DoctoRot
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- Z650Spirit
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Pablo.
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- DoctoRot
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- DoctoRot
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I checked the plugs and was very surprised. number 1 is lean and number 2 is rich. I checked the compression because the head gasket is leaking pretty good on the left side (which apparently is common) , and both cylinders have 170psi. I just got some OEM pilot jets so i guess i will put those in even tough i don't think thats an issue anymore. Also gonna check the float levels and the timing advancer. Any suggestions?? this thing is driving me crazy, but from first impressions it seems like a fun little bike, especially when it has an even power band.
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- Patton
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DoctoRot wrote: ... number 2 is rich... I checked the compression because the head gasket is leaking pretty good on the left side (which apparently is common) , and both cylinders have 170psi. I just got some OEM pilot jets so i guess i will put those in even tough i don't think thats an issue anymore. Also gonna check the float levels and the timing advancer. Any suggestions?? this thing is driving me crazy, but from first impressions it seems like a fun little bike, especially when it has an even power band.
....
Perhaps the fuel level is too high in #2 carb and causing an excessively rich mixture.
If not already done, would perform the clear tube test to assure fuel levels are within specs.
Good Fortune!
1973 Z1
KZ900 LTD
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- DoctoRot
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I wish i could get some new carbs boots for this thing so i could take that out of the equation but i cant find any. Also im not sure i'm setting the timing right. I am setting it per the FSM but when i check it with a timing light it appears to be slightly off at idle and when i rev to 3500 it doesn't align with the right of the two marks. it aligns with the left. I pulled the points plate off and checked the advancer and lubed it. it seems ok, the springs are a bit soft it seems but everything seems to work, and i don't think this would contribute to the high idle
any suggestions for carb boot replacements?
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