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1st gear, low rpm hesitation... pilot jet?
- Bicycle Lee
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23 Aug 2009 13:35 #315970
by Bicycle Lee
1978 KZ1000 police
1st gear, low rpm hesitation... pilot jet? was created by Bicycle Lee
the subject line pretty much says it all, but here's the story:
I finally got my 78 KZ1000 police bike back on the road after a few years of it being in pieces.
I'm still running my BS34's on it for now. I have a set of 28's laying around that I might get around to using at some point...but....
The bike has stock bore, new rings, polished ports, new valves, 4-1 header with a big V&H megaphone...
Anyway, I found that I had some low rpm hesitation in first gear. Could that be a pilot jet issue? It also has trouble keeping a steady idle.
Any ideas?
I finally got my 78 KZ1000 police bike back on the road after a few years of it being in pieces.
I'm still running my BS34's on it for now. I have a set of 28's laying around that I might get around to using at some point...but....
The bike has stock bore, new rings, polished ports, new valves, 4-1 header with a big V&H megaphone...
Anyway, I found that I had some low rpm hesitation in first gear. Could that be a pilot jet issue? It also has trouble keeping a steady idle.
Any ideas?
1978 KZ1000 police
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- Kawickrice
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- After Monday & Tuesday, even the calendar says WTF
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23 Aug 2009 14:41 #315982
by Kawickrice
73 Kawasaki Z1
07 HD CVO Ultra Classic
82 Suzuki GS 1100
74 Yamaha RD 350 (My two stroke toy)
77 Kawasaki KZ 650B-1 (My putt around bike)
80 Indian Moped (My American Iron)
1
Long Gone
75 Suzuki GT550
74 GT 380
79 RD 400 Daytona Special
72 Honda CL 175
74 Honda QA 50
Tampa FL
Replied by Kawickrice on topic 1st gear, low rpm hesitation... pilot jet?
I would suspect the pilot circuit. With the symptoms you describe, hesitation, and erratic idle.
73 Kawasaki Z1
07 HD CVO Ultra Classic
82 Suzuki GS 1100
74 Yamaha RD 350 (My two stroke toy)
77 Kawasaki KZ 650B-1 (My putt around bike)
80 Indian Moped (My American Iron)
1
Long Gone
75 Suzuki GT550
74 GT 380
79 RD 400 Daytona Special
72 Honda CL 175
74 Honda QA 50
Tampa FL
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- bountyhunter
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23 Aug 2009 14:45 - 23 Aug 2009 14:46 #315984
by bountyhunter
1979 KZ-750 Twin
Replied by bountyhunter on topic 1st gear, low rpm hesitation... pilot jet?
Low RPM hesitation:
1) Fuel level in bowls
2) pilot jets/adjustment
3) needle position too lean? (lean running from headers and/or pods)
4) vacuum leak
1) Fuel level in bowls
2) pilot jets/adjustment
3) needle position too lean? (lean running from headers and/or pods)
4) vacuum leak
1979 KZ-750 Twin
Last edit: 23 Aug 2009 14:46 by bountyhunter.
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- Bicycle Lee
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23 Aug 2009 14:45 #315985
by Bicycle Lee
1978 KZ1000 police
Replied by Bicycle Lee on topic 1st gear, low rpm hesitation... pilot jet?
yeah.... I kinda figured... I'll pull the bank and maybe go up a size...or two...
1978 KZ1000 police
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- timebomb33
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23 Aug 2009 15:46 #315998
by timebomb33
1973 z1 2-1974z1-a,2-1975z1-b dragbikes1015cc+1393cc, 1977kz1000,1978kz1000,1981kz1000j, 1997 zx-11, 2000 z12r,1428turbo nitrous pro-mod and a shit load of parts thats all for now leader sask.,CANADA
I THINK MY POWERBAND BROKE
Replied by timebomb33 on topic 1st gear, low rpm hesitation... pilot jet?
you should try giving them a good cleaning first the double check there are no air leaks past the intake boot's. does it return to idle or does it hang up and come back slowly.what size of engine did the carb's come from to begin with. the 34's i mean. because if they came from a 1000 i wouldn't think you would have to change your jetting much to make them work fairly good it really sounds like partially plugged pilot jets or the entire circuit.
1973 z1 2-1974z1-a,2-1975z1-b dragbikes1015cc+1393cc, 1977kz1000,1978kz1000,1981kz1000j, 1997 zx-11, 2000 z12r,1428turbo nitrous pro-mod and a shit load of parts thats all for now leader sask.,CANADA
I THINK MY POWERBAND BROKE
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- Bicycle Lee
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24 Aug 2009 11:12 #316128
by Bicycle Lee
1978 KZ1000 police
Replied by Bicycle Lee on topic 1st gear, low rpm hesitation... pilot jet?
the 34's are the carbs the bike came with... to be fair, the bike never ran perfect before so to say that the jets are the right size is a tough sell haha. It runs great now besides the idle. It does hang up and then rumble back down... then cuts usually. I've found holding it just under 2k rpm is ok, but it still is erratic. PLus my petcock seems to be malfunctioning now... haha...
it never ends, does it?
it never ends, does it?
1978 KZ1000 police
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- Bicycle Lee
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26 Aug 2009 10:23 #316539
by Bicycle Lee
1978 KZ1000 police
Replied by Bicycle Lee on topic 1st gear, low rpm hesitation... pilot jet?
so I went larger on my pilot jets... from 17.5 to 22.5....
still had a little hesitation on acceleration, but my idle seemed a little better... still slightly erratic. Now I have hesitation from 3K to 5K rpm....
still had a little hesitation on acceleration, but my idle seemed a little better... still slightly erratic. Now I have hesitation from 3K to 5K rpm....
1978 KZ1000 police
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- timebomb33
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26 Aug 2009 11:42 #316554
by timebomb33
1973 z1 2-1974z1-a,2-1975z1-b dragbikes1015cc+1393cc, 1977kz1000,1978kz1000,1981kz1000j, 1997 zx-11, 2000 z12r,1428turbo nitrous pro-mod and a shit load of parts thats all for now leader sask.,CANADA
I THINK MY POWERBAND BROKE
Replied by timebomb33 on topic 1st gear, low rpm hesitation... pilot jet?
raise up your needles 1 notch and give that a try it should help out in the middle.
1973 z1 2-1974z1-a,2-1975z1-b dragbikes1015cc+1393cc, 1977kz1000,1978kz1000,1981kz1000j, 1997 zx-11, 2000 z12r,1428turbo nitrous pro-mod and a shit load of parts thats all for now leader sask.,CANADA
I THINK MY POWERBAND BROKE
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- Bicycle Lee
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26 Aug 2009 12:35 #316557
by Bicycle Lee
1978 KZ1000 police
Replied by Bicycle Lee on topic 1st gear, low rpm hesitation... pilot jet?
I'm not sure if my needles are adjustable?? Maybe I'm an idiot, but I don't think they are.
1978 KZ1000 police
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- harm
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- Tom
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26 Aug 2009 16:35 #316587
by harm
Tom
Holland, MI
1980 KZ550 ELR
2011 Concours14
2017 KX450 [/color]
Replied by harm on topic 1st gear, low rpm hesitation... pilot jet?
I'm not sure i would have changed the pilots:) I would definitely change the needle position, remember, to richin it up you must lower the clip which raises the needle. The slightly eratic behaviour may suggest a carb sync.
Tom
Holland, MI
1980 KZ550 ELR
2011 Concours14
2017 KX450 [/color]
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