What position to set the needle height
- cruspeed
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18 May 2010 11:55 #368771
by cruspeed
78 KZ1000 project X 2
What position to set the needle height was created by cruspeed
I striped down the carbs to completely clean them and the PO has already put a jet kit in it. 125 is stamped on the main jet and it looks like a small 20 stamped on the pilot. After removing everything that I could, I took a needle out and noticed that the clip is on the bottom of the needle. I guess that they are all like this seeing I took apart another and it was the same.
The only information that I can find is about moving the clip up and down to change the mixture but should I start out with the clip at the very bottom? Bike has pods, 4 to 1, and 1075 kit. The PO had velocity stacks on the bike, so I guess there wasn't much vacuum so he needed it so low. Any information will help, thanks!
The only information that I can find is about moving the clip up and down to change the mixture but should I start out with the clip at the very bottom? Bike has pods, 4 to 1, and 1075 kit. The PO had velocity stacks on the bike, so I guess there wasn't much vacuum so he needed it so low. Any information will help, thanks!
78 KZ1000 project X 2
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- Patton
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18 May 2010 12:27 - 18 May 2010 12:36 #368777
by Patton
1973 Z1
KZ900 LTD
Replied by Patton on topic What position to set the needle height
Oem position was middle clip. And that's where I would put it as best first guess.
The clip position adjusts fuel mixture ratio in mid-throttle range.
With carbs otherwise perfect, including fuel levels and assured adequate fuel supply (plus good properly timed spark and acceptable compression with valve clearances to spec), if mid-range is lean, may then drop one clip position on jet needle (toward pointed end) and test run for effect.
Good Fortune!
The clip position adjusts fuel mixture ratio in mid-throttle range.
With carbs otherwise perfect, including fuel levels and assured adequate fuel supply (plus good properly timed spark and acceptable compression with valve clearances to spec), if mid-range is lean, may then drop one clip position on jet needle (toward pointed end) and test run for effect.
Good Fortune!
1973 Z1
KZ900 LTD
Last edit: 18 May 2010 12:36 by Patton.
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- TeK9iNe
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18 May 2010 13:56 #368794
by TeK9iNe
Motorcycle Shop Owner/Operator
79 Kawie Z1000 LTD
81 Kawie Z1000 CSR
83 Honda VT750C A
85 Kawie GPZ900 A2
86 Zukie GS1150 EG
93 Yamie XV1100 E
Lucky to have rolled many old bikes through my doors
Replied by TeK9iNe on topic What position to set the needle height
The stock position with a jet kit on those carbs is the second slot from the top.
The mixture screws are for idle.
The pilots are for cruise and idle/cruise/accell transition.
The needles are all about accelleration.
The mains are for WOT only, and should provide a little more fuel to the ratio than the needle for the high demand on the engine.
If you have problems (hesitating or lag) twisting the throttle and accellerating quickly/smoothly from 1/4 all the way to almost full throttle, its the needle. Change the clip position and retest.
GL!
The mixture screws are for idle.
The pilots are for cruise and idle/cruise/accell transition.
The needles are all about accelleration.
The mains are for WOT only, and should provide a little more fuel to the ratio than the needle for the high demand on the engine.
If you have problems (hesitating or lag) twisting the throttle and accellerating quickly/smoothly from 1/4 all the way to almost full throttle, its the needle. Change the clip position and retest.
GL!
Motorcycle Shop Owner/Operator
79 Kawie Z1000 LTD
81 Kawie Z1000 CSR
83 Honda VT750C A
85 Kawie GPZ900 A2
86 Zukie GS1150 EG
93 Yamie XV1100 E
Lucky to have rolled many old bikes through my doors
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