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Jet Kit Availability?
- OutsiderKZ900A4
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Any help would be appreciated. I tried to search but didn't come up with much...
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- Patton
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www.z1enterprises.com/ItemDetails.aspx?i...+1977-80&item=DJ2304
The jet needle is particularly important to performance throughout mid-range.of the carb.
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1973 Z1
KZ900 LTD
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- OutsiderKZ900A4
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The bike is a 1976 KZ900A4, it has a Kerker 4 into 1 exahust, K&N Pod filters and a Dyna ignition system on it. What would you recommend as a good starting point for jetting, Main Jet and Pilot Jet. I am not sure if the needles are adjustable in these or not but if it is like my triples of the similar vintage they should be?
Any help would be appreciated, thank you.
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- Patton
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Any advice from the folks at Z1E?
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1973 Z1
KZ900 LTD
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- Patton
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With non-carb components near-perfect (compression; valve clearances; ignition; fuel supply) and carb in as-new condition, would first test ride Kerker and pods with stock carbs (stock jets and settings), as these bikes performed very well in such configuration when relatively new, even with over-bores up to 1100.
If roadside plug readings incident to throttle-chop testing indicates lean mixture at WOT, could go one size larger main jet.
So long as low rpm is steady, with strong pull-away from idle, there's imo no real need for larger pilot jets.
It's doubtful imo that a different jet needle clip position would be needed.
Remember that carbs should not be used in attempting to offset deficiencies in non-carb related components.
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1973 Z1
KZ900 LTD
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- Jeff.Saunders
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The KZ900 tended to be a rich setup to start with, so I would probably only go to 120 or 122.5 main and 20 pilot jets, then raise the needle (lower the clip) one notch.
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- OutsiderKZ900A4
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Patton wrote: Stock KZ900 carbs are very accommodating and not overly lean with original jettings and jet needle middle-clip positions.
With non-carb components near-perfect (compression; valve clearances; ignition; fuel supply) and carb in as-new condition, would first test ride Kerker and pods with stock carbs (stock jets and settings), as these bikes performed very well in such configuration when relatively new, even with over-bores up to 1100.
If roadside plug readings incident to throttle-chop testing indicates lean mixture at WOT, could go one size larger main jet.
So long as low rpm is steady, with strong pull-away from idle, there's imo no real need for larger pilot jets.
It's doubtful imo that a different jet needle clip position would be needed.
Remember that carbs should not be used in attempting to offset deficiencies in non-carb related components.
Good Fortune!
The biggest issue the bike seems to have is it is lean on idle. The previous owner turned the air screws in almost all the way to make it want to idle right. This leads me to believe that the pilot jets need to be bigger. My Dad ran into a similar issue on his modified S3 (400 triple) that ended up being mostly taken care of with H2 pilot jets. I have 20 and 22.5 pilot jets ordered from Z1E. It runs good from mid range on up.
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- Patton
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OutsiderKZ900A4 wrote: ...The biggest issue the bike seems to have is it is lean on idle. The previous owner turned the air screws in almost all the way to make it want to idle right. This leads me to believe that the pilot jets need to be bigger... I have 20 and 22.5 pilot jets ordered from Z1E. It runs good from mid range on up.
Would also consider possibility of an imperfectly clean pilot circuit. For instance, perhaps the orifice is partially obstructed where the pilot circuit mixture enters the main carb bore (see #6 in the following illustration.
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1973 Z1
KZ900 LTD
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- OutsiderKZ900A4
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When I pull the carbs, I am going to clean them. I can't see all 4 carbs having the exact lean issue but they will definitely be cleaned.Patton wrote:
OutsiderKZ900A4 wrote: ...The biggest issue the bike seems to have is it is lean on idle. The previous owner turned the air screws in almost all the way to make it want to idle right. This leads me to believe that the pilot jets need to be bigger... I have 20 and 22.5 pilot jets ordered from Z1E. It runs good from mid range on up.
Would also consider possibility of an imperfectly clean pilot circuit. For instance, perhaps the orifice is partially obstructed where the pilot circuit mixture enters the main carb bore (see #6 in the following illustration.
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- Patton
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And assure that the pointed tips of the pilot screws are in good condition, and that the pilot screw o'rings are present and correct and in good condition.
Presumably, the pilot screws are the correct pilot screws for the carbs at hand, and haven't been unknowingly replaced by similar pilot screws from different model carbs.
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1973 Z1
KZ900 LTD
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- OutsiderKZ900A4
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Any suggestions where to start?
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- OutsiderKZ900A4
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