Just not running hard enough
- drewd2385
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Just not running hard enough
26 Aug 2015 15:25
Ok guys I have been building a stick kz1000 mkII drag bike and I took it for the first test ride today and it just doesn't feel like it's that fast my as 900 feels faster I have took the carbs apart multiple times and finnaly got them to were it will idle and run half assed with the choke half way off I know the main jets are 127.5 don't know what the pilots are but I have Vance and Hines sidewinder pipes no baffle and no air boots I really need some help to try and get this thing to run better times then my 900 she ran 10.88 at 127 I would like to be close if not smoking that can any one help? I am a noob
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- Patton
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Re: Just not running hard enough
26 Aug 2015 15:47drewd2385 wrote: Ok guys I have been building a stick kz1000 mkII drag bike and I took it for the first test ride today and it just doesn't feel like it's that fast my as 900 feels faster I have took the carbs apart multiple times and finnaly got them to were it will idle and run half assed with the choke half way off I know the main jets are 127.5 don't know what the pilots are but I have Vance and Hines sidewinder pipes no baffle and no air boots I really need some help to try and get this thing to run better times then my 900 she ran 10.88 at 127 I would like to be close if not smoking that can any one help? I am a noob
no air boots -- is this meaning nothing on intake side of carbs, not even carb hoses or stacks?
What carbs?
Pilots don't influence wot.
Improved performance at wot with partial choke indicates too lean mixture which could result from any of several possible reasons.
What tuning has been done?
Good Fortune!

1973 Z1
KZ900 LTD
KZ900 LTD
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- Tyrell Corp
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Re: Just not running hard enough
26 Aug 2015 16:06
The bike won't run without half choke and you are asking why it wont do 10.5 at 130mph?
1980 Gpz550 D1, 1981 GPz550 D1. 1982 GPz750R1. 1983 z1000R R2. all four aces
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- 650ed
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Re: Just not running hard enough
26 Aug 2015 16:12
I think he's putting us on. :laugh: Ed
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
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- drewd2385
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Re: Just not running hard enough
26 Aug 2015 16:13
It's a stock is mkII 1000 motor and carbs I believe they are 28s smoothbores and they are jetted with 127.5s for the mains not sure about pilots but it will idle and stay running with the choke half way off but dissent pull or clone real hard like she should and yes no air boots or stack just straight carbs by buddy runs his carbs like that and so do a lot of other fellow drag racers just do t know where to go maybe my jets are to big for this motor and carb??? I'm doing a compression test tonight after work
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- drewd2385
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Re: Just not running hard enough
26 Aug 2015 16:24 - 26 Aug 2015 16:24Tyrell Corp wrote: The bike won't run without half choke and you are asking why it wont do 10.5 at 130mph?
Yes I'm asking why do you know what's going on? Like I said I am a noob and just want this thing to run to it's full potential
Last edit: 26 Aug 2015 16:24 by drewd2385.
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- SWest
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Re: Just not running hard enough
26 Aug 2015 17:15
I don't know about YOUR 900 but the Z1's could pull on the stock 1000's. I did it. Smaller carbs heavier crank made them sluggish compared. Sounds with what you have, it won't run for SHT without proper jetting and no baffle costs you top end. Yeah, I know other guys run them that way but when they come up on a tuned 900/1015 with cams, tuned exhaust, there's no race. :whistle:
When was the last time the valves were adjusted? Routine maintenance, then try to dial in the carbs.
Steve
When was the last time the valves were adjusted? Routine maintenance, then try to dial in the carbs.

Steve
Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229
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Re: Just not running hard enough
26 Aug 2015 17:33
Sorry to take the piss, I think you are miles out on your main jetting, have you experimented going up on the main jet or lifting the needles? takes a bit of experimentation, and balls of steel if you are going WOT flat out on a a litre plus bike.
Running straight through without filters or stacks can work, not ideal for long engine life though. Likewise, I've gone straight through on pipes and it can work quite nicely . Not sure about no baffles costing top end, i'd say the opposite actually.
It is all about getting everything working together. I'd start with basic main jet tuning, try to get that as good as you can. hopefully someone with 28 smoothbore experience on one of these will chip in and point you in the right direction. good luck.
Running straight through without filters or stacks can work, not ideal for long engine life though. Likewise, I've gone straight through on pipes and it can work quite nicely . Not sure about no baffles costing top end, i'd say the opposite actually.
It is all about getting everything working together. I'd start with basic main jet tuning, try to get that as good as you can. hopefully someone with 28 smoothbore experience on one of these will chip in and point you in the right direction. good luck.
1980 Gpz550 D1, 1981 GPz550 D1. 1982 GPz750R1. 1983 z1000R R2. all four aces
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- spdygon
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Re: Just not running hard enough
26 Aug 2015 18:34
Stock motor and open exhaust....
Iv run a 1000 and 900 this way with 26mm and 29mm smooth bores and both use the same mains and pilots
120 main
17.5 pilots
Iv run a 1000 and 900 this way with 26mm and 29mm smooth bores and both use the same mains and pilots
120 main
17.5 pilots
1982 GS1000sz Katana ( #15...17K Miles)
1982 GS1000sz Katana ( # 297....7100k Miles)
1978 Kz1000 Z1R. 10K Miles1
1978 kz1000 z1r 27k miles
1977 KZ 1000 A ( Project ) 54K Miles
1976 Kz900A4 (Red)21K miles
1976 Kz900A4 ( Red)7500 miles
1974 Z1 900 project
1982 GS1000sz Katana ( # 297....7100k Miles)
1978 Kz1000 Z1R. 10K Miles1
1978 kz1000 z1r 27k miles
1977 KZ 1000 A ( Project ) 54K Miles
1976 Kz900A4 (Red)21K miles
1976 Kz900A4 ( Red)7500 miles
1974 Z1 900 project
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- drewd2385
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Re: Just not running hard enough
26 Aug 2015 20:01
I haven't rode the bike on the track just out in the country and it just ran like shit just didn't pull at all but I'm just wondering if the jets that's in it are to big ? I ride a zx9r and the kz honestly felt like a 250 enduro lol compared to that and the kz took forever to rap to full rpms if I am doing a compression test on it soon and getting those jets but does any one know about the the fuel accelerator that's on my carbs?
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- Patton
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Re: Just not running hard enough
26 Aug 2015 21:43
Plug readings?
Good Fortune!
Good Fortune!

1973 Z1
KZ900 LTD
KZ900 LTD
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- drewd2385
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Re: Just not running hard enough
26 Aug 2015 22:43
#1&2 cylinder black with oil 3 and 4 are tan and dry
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