76 KZ900

mvent
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19 Mar 2023 10:05 #881778 by mvent

Replied by mvent on topic 76 KZ900

Pulled carbs again, blew them out with compressed air, pilot jets clear #4 head pipe not getting hot, #3 better but not close to cylinder 1 and 2. temp at spark plugs are pretty close on all 4. Switched plug wire from 1 and 4 no change, switched out spark plugs no change, hot compression on #4 150, other 3 between 135-150. I guess this narrows it down to carburetor ? Float height same on all carbs and all getting fuel. Ultra sonic next. Any ideas ?

76 KZ900
76 XLCH
78 KZ1000
04 FLSTFI 120 ci

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Mikaw
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19 Mar 2023 11:18 #881782 by Mikaw

Replied by Mikaw on topic 76 KZ900

You make a very confusing comment if I read correctly. You say the IR temps are very similar at the spark plugs, but you have extreme temp difference at the down (head) tube. This doesn’t seem possible. Is it possible you have a blockage in the down tube. Critter nest? I bought an once engine that had short 6-8 inch sections of down tubes affixed and mice had called up into the open tube and built nest in one of them.

1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.

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mvent
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19 Mar 2023 11:46 #881783 by mvent

Replied by mvent on topic 76 KZ900

Mikaw funny you said that it did cross my mind but I thought between the exhaust heat and pressure it would have blown it out.

76 KZ900
76 XLCH
78 KZ1000
04 FLSTFI 120 ci

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Mikaw
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19 Mar 2023 11:55 #881784 by Mikaw

Replied by Mikaw on topic 76 KZ900

Not sure what else could cause such a temp differential between the plug and the down tube.

1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.

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Scirocco
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Never change a running system

19 Mar 2023 14:45 - 19 Mar 2023 14:56 #881794 by Scirocco

Replied by Scirocco on topic 76 KZ900

Remove the bleeder tubes under the main jets and give them a clean. Compressed air is not a cleaning medium!Did you inspect and set the pilot air mixture screws to 1 1/2 - 1 3/4 turns out? A broken air mixture screws tip can made your day!Are the carbs mechanical/vaccum synced?

My 1975 Z 1 B 900 Project

www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode

Last edit: 19 Mar 2023 14:56 by Scirocco.

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mvent
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19 Mar 2023 15:52 #881795 by mvent

Replied by mvent on topic 76 KZ900

Scirocco, all above mentioned has been done air screws are 1 1/2 turns out. Mechanically synched for now. Thanks for the suggestions. These are Z1b carbs, are pilot jets supposed to have o rings? none of these do.

76 KZ900
76 XLCH
78 KZ1000
04 FLSTFI 120 ci

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Scirocco
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Never change a running system

19 Mar 2023 16:21 #881798 by Scirocco

Replied by Scirocco on topic 76 KZ900

These are air/fuel mixer screws were the tip was broken and stuck in the carb body.

My 1975 Z 1 B 900 Project

www.kzrider.com/forum/11-projects/605133...ears-deep-sleep-mode

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Mikaw
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19 Mar 2023 19:28 #881807 by Mikaw

Replied by Mikaw on topic 76 KZ900

Here this will help with item terms. There are no ORings on the pilot jet #21, non on the main jet emulsion tube/ jet holder #20, nor on the pilot air adjustment screw #23.

1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.

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mvent
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20 Mar 2023 07:39 - 20 Mar 2023 09:41 #881816 by mvent

Replied by mvent on topic 76 KZ900

This is a picture into exhaust port of #4 cylinder

76 KZ900
76 XLCH
78 KZ1000
04 FLSTFI 120 ci

Last edit: 20 Mar 2023 09:41 by Street Fighter LTD.

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Mikaw
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20 Mar 2023 07:47 #881817 by Mikaw

Replied by Mikaw on topic 76 KZ900

Looks like it’s been running rich or burning some oil, but I don’t see anything “Abbynormal”.

1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.

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Wookie58
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20 Mar 2023 07:50 #881818 by Wookie58

Replied by Wookie58 on topic 76 KZ900

mvent wrote:
Pulled carbs again, blew them out with compressed air, pilot jets clear #4 head pipe not getting hot, #3 better but not close to cylinder 1 and 2. temp at spark plugs are pretty close on all 4. Switched plug wire from 1 and 4 no change, switched out spark plugs no change, hot compression on #4 150, other 3 between 135-150. I guess this narrows it down to carburetor ? Float height same on all carbs and all getting fuel. Ultra sonic next. Any ideas ?

Have you tried switching the actual coils ?

1982 KZ1000 Ltd
www.kzrider.com/forum/11-projects/617631...-82-begins?start=192
kzrider.com/filebase-alias?view=download...d-fault-diagnosis&ca

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mvent
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20 Mar 2023 13:50 #881834 by mvent

Replied by mvent on topic 76 KZ900

Wookie I have not, switching wires between 1 and 4 then spark plugs without change my assumption was that would eliminate any electrical problems with coils, wires and spark plugs.

76 KZ900
76 XLCH
78 KZ1000
04 FLSTFI 120 ci

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76 KZ900

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