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Sorry another jetting issue. 79 kz1000B
- 79Ltd1000
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79 ltd 1000
2008 Silverado 4\" lift
1994 explorer 9\" lift on 35s
I might not know, but i\'ll try.
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- Patton
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If reading correctly, you have doubts about the Emgo pods, are having engine performance issues between 4000-5500 rpm, and get lean plug reading after high speed plug chop.
Are these the stock carbs (believed Mikuni 28mm manual slide with side located pilot air screw adjusters)? Looks like you went up two sizes on the main jets and one size on the pilots.
How was the bike set up when it ran great before? Airbox? Were the pods and 4>1 installed at the same time the jets were changed? Did the Mac replace a more restrictive (stock?) exhaust? Are the Macs open or using baffles?
1973 Z1
KZ900 LTD
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- 79Ltd1000
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79 ltd 1000
2008 Silverado 4\" lift
1994 explorer 9\" lift on 35s
I might not know, but i\'ll try.
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- Patton
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the mac replaced the stock exhaust. before it was stock pipes and stock air box. it ran great. the filter and pipe was changed, the mac pipe is baffled. they were all done at the same time. lean with a bad dead spot with backfiring. i don't believe my stock carbs have the adjustable needle and i don't want to take them out of sync adjusting the air screws.
While the Kawasaki.com diagram may be incorrect, it seems to show the 79KZ1000LTD carb jet needle with different clip notches, and pilot fuel mixture screw on the bottom (as opposed to a side-located air screw).
You could try enrichening the pilot circuit mixture by turning the bottom located adjustment screw counter-clockwise (screw it out a little, say 1/4 - 1/2 turn) as an experiment for any effect on the 4000-5500 rpm problem. (If a side located air screw, turn it in clockwise to enrich). Pilot screw adjustment (bottom or side) does not affect existing synch settings.
WOT mixture is primarily dependent on the main jet size, regardless of the jet needle clip position.
I agree it would be best to re-sync after relocating clip position on the jet needle.
Are all other non-carb components up to snuff (compression, ignition, fuel delivery, etc.)?
I have read that pods are more difficult than an airbox filter to obtain optimum fuel mixtures throughout the throttle range.
I expect others will have better and more detailed advice as to best adjustments for your particular setup.
Good Luck!
Here's the diagram.
1973 Z1
KZ900 LTD
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- Becker
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- The Doctor Will Rise Again
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78 KZ750B3
79 KZ400 LTD
78 KZ650C2
79 KZ650C3
78 KZ650B2A
80 KZ650F1
80 KZ650E1
81 CB750K Super Sport
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- bountyhunter
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the mac replaced the stock exhaust. before it was stock pipes and stock air box. it ran great. the filter and pipe was changed, the mac pipe is baffled. they were all done at the same time. lean with a bad dead spot with backfiring. i don't believe my stock carbs have the adjustable needle and i don't want to take them out of sync adjusting the air screws.
I'd try the stock airbox with the MAC pipe. When you change two things at once, you can't tell how much harm is done by each. This kind of story is what I read a lot when people use air pods. My memory is that the 900 - 1000 are particularly nasty to try to get to run with pods.
1979 KZ-750 Twin
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- bountyhunter
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I know everyone asks about it, but nobody ever finishes with thank you that worked. I have a 79 Ltd 1000, chain drive, "if it matters" I read the forum and realized i made a mistake, i bought Emgo filters, i have a mac 4 to 1. i upped my main jets from 117 to 122.5, and my pilots from 15 to 17.5. it ran great before, after pods and pipe, it has more bottom end, cuts out and backfires about 4, pulls hard again after 5500. plugs come out white up top so i figure it's lean. i believe my carbs are 28s.
If it gets strong after 5500, then your main jets are probably large enough and don't need adjusting. You can try going up to the next larger main jet and see if you get more power at the high RPM, wide open throttle range.
"cuts out and backfires about 4"
This sounds like the best "knob" to tweak would be needle position. Rich it to the max and see if it gets better.
1979 KZ-750 Twin
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- wiredgeorge
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wiredgeorge Motorcycle Carburetors
Mico TX
www.wgcarbs.com
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- 79Ltd1000
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79 ltd 1000
2008 Silverado 4\" lift
1994 explorer 9\" lift on 35s
I might not know, but i\'ll try.
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- 79Ltd1000
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79 ltd 1000
2008 Silverado 4\" lift
1994 explorer 9\" lift on 35s
I might not know, but i\'ll try.
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- wiredgeorge
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wiredgeorge Motorcycle Carburetors
Mico TX
www.wgcarbs.com
Too many bikes to list!
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- 79Ltd1000
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79 ltd 1000
2008 Silverado 4\" lift
1994 explorer 9\" lift on 35s
I might not know, but i\'ll try.
Please Log in or Create an account to join the conversation.