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1976 KZ400 questions
- Kitten Tooth
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Thanks guys,
KT
1981 Kawasaki KZ1000-K LTD
1983 Suzuki GS300L-D
1982 Suzuki GS300L-Z sold:(
1976 KZ400D3
1973 Z900... I WISH
DO A BARREL ROLL!!
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- Biquetoast
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- King Jeremy The Wicked
Whoa, that's alot.As most of you know, i just bought a 1976 KZ400S2. i got it running today after cleaning the carburetors last night. It runs but it idles high and the idle screw on the side of the carb isn't even touching the throttle assy. anymore so according to it, its closed. i know i have a vacuum leak somewhere. I need new manifold boots for it because these ones are cracked up bad. i patched them with some silicon and electrical tape but they still aren't sealing. i was wondering if maybe somebody on here might have some boots that they might sell me? the bike revs but the diaphrams don't seem to move up and down... i know they aren't stuck. Is it even possible for the bike to rev if the diaphrams don't open? Also, will the bike run like crap, or not at all with a dead battery in it? mine had a battery in it, but after i while i had to jump it off the car to start it because it went dead after it dying and me restarting it all the time because i couldn't get the carbs right. I would start it with it hooked up to the car battery and as soon as i removed one of the clamps on the jumper cables, the bike would idle way down and die... do you guys know if maybe the bike has a bad charging system? I'll start downloading the manual tonight on that one website but i was wondering if maybe you guys knew what the spark plug gap was for this? I'll post a video of it running:)
Thanks guys,
KT
High idle like that is due to air leaks or lean condition. Could be incorrect float level, choke problems, or air leaks like you suspect. Stock manifolds for the '74 - '76 KZ400's are rare (though you can stumble upon a set once in awhile), so many people are forced to try and find ways to seal old ones. You might also want to make sure the manifolds you have are seated well against the cylinder head. Warning though; if they are stock, and you try to remove them, you will likely break the two screws holding them and you will have to drill them out...
I recommend you continue your plan to get the manual, then sit down and read the whole "Theory of Operation" carb section. So much more will make sense to you. Like for instance, these early models don't have diaphragms, they have an all-metal piston that lifts the main jet needle. The butterflies are opened with the throttle, and that is the revving you noted. The piston will rise as needed if it is able to...
The battery symptoms you describe sound about normal for a dead battery. Honestly though, I've been running my 400 for years on an almost-dead battery. Have you ensured that your possibly-dead battery is topped off with distilled water? and there are ways to test the charging system... I believe that's outlined in the manual too...
And wouldn't you know it, I don't remember the plug gap off the top of my head, but I know it's in the manual...
(1.) '75/'76 KZ400D - Commuter
(2.) '78 KZ750B3 Twin - Commuter
(3.) '78 KZ750B3 Twin - Commuter
(4.) '75 KZ400D - Sold
kz750twins.com
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- anyday
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Thanks for the reply:)
KT
1981 KZ 1000-k, 1982 GS300L-D, 1982 GS300L-Z (parts)
Sioux City, IA
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- loudhvx
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EDIT: I should add, with a totally dead battery, you should have the headlight turned off to start. A headlight acts like a short until the filament heats up. A dead battery may not have enough energy to heat the element so the voltage will stay too low to start. (On my firends bike we wired the ignition switch to have a position with just ignition and no headlight.)
1981 KZ550 D1 gpz.
Kz550 valve train warning.
Other links.
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