High idle
- Bama704
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High idle
05 Mar 2016 11:23
I was out riding a few weeks ago and about 1 1/2 hours into the ride I came to more of a stop and go pace. I noticed the idle kept wanting to climb when I was in neutral, so i adjusted the throttle stop on the carbs and it dropped down. Now to the present, I started the bike up and noticed popping out of the carbs and exhaust for the first few minutes. I went for a ride today, about 5 miles to warm it up and came back home to do some adjustments on the air screw on the side of the carbs. By this time, my RPM's have climbed to 3k when at idle and there is no tension being placed on the set screw/throttle stop. When I started to adjust the air screws II seated each screw then started to back them out to the same number of turns on each carb, and the rpm's continued to climb.
While I was out riding around 1/8 - 1/4 throttle was bogging down and sounded like crap until I would get past the 1/4 mark and everything would operate as normal. Does this mean that I need to increase the size of my pilot jets?
What is the cause for the high RPM's?
Do you think it could be an air leak on my carb boots? I will try shooting some wd-40 on the boots when I get a chance.
While I was out riding around 1/8 - 1/4 throttle was bogging down and sounded like crap until I would get past the 1/4 mark and everything would operate as normal. Does this mean that I need to increase the size of my pilot jets?
What is the cause for the high RPM's?
Do you think it could be an air leak on my carb boots? I will try shooting some wd-40 on the boots when I get a chance.
1977 KZ900
Carbs are late model 1975 28mm
Carbs are late model 1975 28mm
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- Nessism
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Re: High idle
05 Mar 2016 12:14
Sounds like an air leak. Spraying WD-40 or similar on the boots will only register gross leaks and is not a reliable method to find air leaks.
Ed
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0
www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know
1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0
www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know
1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread
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- Bama704
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Re: High idle
06 Mar 2016 07:42
If wd-40 isn't a good option, do you have any suggestions in how to search for air leaks
1977 KZ900
Carbs are late model 1975 28mm
Carbs are late model 1975 28mm
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- Patton
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Re: High idle
06 Mar 2016 07:55 - 06 Mar 2016 07:56
WD40 ingested through an air leak should cause smoke from the exhaust (in addition to a change in rpm).
Other spray mediums could include carb cleaner, starter fluid, and propane. All with the idea that ingestion should result in a change in rpm.
Would also check integrity of the caps/plugs on the vac nipples, and connections between the carbs and carb holders such as a loose clamp,
Good Fortune!
Other spray mediums could include carb cleaner, starter fluid, and propane. All with the idea that ingestion should result in a change in rpm.
Would also check integrity of the caps/plugs on the vac nipples, and connections between the carbs and carb holders such as a loose clamp,
Good Fortune!
1973 Z1
KZ900 LTD
KZ900 LTD
Last edit: 06 Mar 2016 07:56 by Patton.
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- jakedude
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Re: High idle
06 Mar 2016 08:27
My KZ1000-p7 ran like that when my pilot jets were adjust too rich. The KZ1000-p7 uses mikuni BS34 carburetors. I don't know what carbs you are running but my guess is you have pilot screws to adjust this type of jet as well. Other symptoms include needing little or no choke to start when cold with rough running if you use the choke, and slow return to idle RPM after dropping the throttle from high RPM. When dropping the throttle, the RPM should quickly drop to idle.
Nothing lasts, nothing is finished, and nothing is perfect.
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- Bama704
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Re: High idle
07 Mar 2016 06:04
I have 1975 late model 28mm carbs on mine and I do need to have full choke to cold start. It idles fine when it is cold but once it is warmed up the rpm's surge. I have the side pilot/air screws that I have adjusted and when fully seated there is no difference, rpm's increase when i open them out 1 1/4 turns.
I have not sprayed any WD40 but i did check to see if my clamps were tight as well as the integrity of the vacuum nipples. All is tight and the vac nipples are ok, they are not hard and cracked.
I have not sprayed any WD40 but i did check to see if my clamps were tight as well as the integrity of the vacuum nipples. All is tight and the vac nipples are ok, they are not hard and cracked.
1977 KZ900
Carbs are late model 1975 28mm
Carbs are late model 1975 28mm
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- strum
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Re: High idle
07 Mar 2016 07:14 - 07 Mar 2016 07:15
Vacuum leak(s) would be my first guess but also youll want to check your air filter if your running stock airbox. and fuel flow .
You ever notice an engine when its running out of fuel take off to a high idle?
Just a thought but you should check the fuel filter and petcock . make sure fuel is flowing well.
After that , if those carbs havnt been apart for a while then im sure they need to be cleaned and float levels set.
You ever notice an engine when its running out of fuel take off to a high idle?
Just a thought but you should check the fuel filter and petcock . make sure fuel is flowing well.
After that , if those carbs havnt been apart for a while then im sure they need to be cleaned and float levels set.
Blairsville Ga.
1980 KZ1000 Shaft (sold and missed already)
2003 ZRX 1200R (sold)
2003 Concours ZG1000 (just purchased)
1980 KZ1000 Shaft (sold and missed already)
2003 ZRX 1200R (sold)
2003 Concours ZG1000 (just purchased)
Last edit: 07 Mar 2016 07:15 by strum.
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- Bama704
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Re: High idle
07 Mar 2016 07:21
I had the carbs off back in late December to set the float heights. During that time I got a new Pingle petcock, so fuel is flowing fine, also replaced my inline fuel filter at that same time.
I am running a dual pod setup on my carbs
I am running a dual pod setup on my carbs
1977 KZ900
Carbs are late model 1975 28mm
Carbs are late model 1975 28mm
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- Kidkawie
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Re: High idle
07 Mar 2016 08:46
If you can blip the throttle and it backs down to normal rpm you need to clean and lube the advancer.
1975 Z1 900
1994 KX250 Supermoto
2004 KX125
1994 KX250 Supermoto
2004 KX125
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- KZB2 650
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Re: High idle
07 Mar 2016 08:59
I bought a used set of 900 carb holders in 83 to mount my smooth bores and by 2004 they were so cracked up I had to go back with the stockers...... not saying this is the problem but like others have said maybe ...... another thing I've read is to idle the bike as low as possible when spraying the manifolds to increase vacuum but like Nessium says guess its still a crap shoot checking them this way.
1978 KZ650 b-2
700cc Wiseco kit 10 to 1.
1980 KZ750 cam, ape springs, stock clutch/ Barnett springs.
Vance and Hines Header w/ comp baffle and Ape pods, Dyna S and green coils, copper wires.
29MM smooth bores W/ 17.5 pilots, 0-6s and 117.5 main
16/42 gearing X ring chain and alum rear JT sprocket.
700cc Wiseco kit 10 to 1.
1980 KZ750 cam, ape springs, stock clutch/ Barnett springs.
Vance and Hines Header w/ comp baffle and Ape pods, Dyna S and green coils, copper wires.
29MM smooth bores W/ 17.5 pilots, 0-6s and 117.5 main
16/42 gearing X ring chain and alum rear JT sprocket.
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- Bama704
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Re: High idle
07 Mar 2016 13:40
When I blip the throttle the rpms will take a few seconds to come back down at 2-3k. I was able to spray WD40 with no change in rpm's. Do yall think the next step is to take the carbs off, clean the jets with small wire and blow the passage ways with carb spray?
1977 KZ900
Carbs are late model 1975 28mm
Carbs are late model 1975 28mm
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- SWest
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Re: High idle
07 Mar 2016 15:22
Rule out the advancer first.
Steve
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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