Idling speed when warm
- KZShipwreck
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Idling speed when warm
18 Mar 2015 13:51
Hey Guys,
I am new here and thought I would pick your brains for some advice.
I recently got an 81 KZ750 4 cylinder from a friend. The bike was not running had an oil and a gas leak and he just did not want to deal with it so he gave it to me.
Now after a can of sea foam through the gas the bike runs like a dream. The gas leak I fixed and a bottle of stop leak fixed the oil leak for the short term (I know I will need to deal with that soon)
Recently I noticed that when the bike is cold it idles just fine but after riding a few miles when the engine is nice and hot it idles at around 3000 RPM's and the bike is REALLY heavy on gas I get about 70 miles on the 3 gallon tank before needing to fill up again.
Would you guys happen to know what could be wrong with this bike? Any ideas will be greatly appreciated.
I am new here and thought I would pick your brains for some advice.
I recently got an 81 KZ750 4 cylinder from a friend. The bike was not running had an oil and a gas leak and he just did not want to deal with it so he gave it to me.
Now after a can of sea foam through the gas the bike runs like a dream. The gas leak I fixed and a bottle of stop leak fixed the oil leak for the short term (I know I will need to deal with that soon)
Recently I noticed that when the bike is cold it idles just fine but after riding a few miles when the engine is nice and hot it idles at around 3000 RPM's and the bike is REALLY heavy on gas I get about 70 miles on the 3 gallon tank before needing to fill up again.
Would you guys happen to know what could be wrong with this bike? Any ideas will be greatly appreciated.
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- Nessism
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Re: Idling speed when warm
18 Mar 2015 15:02
You might want to do some maintenance on the bike to see if the situation improves. Clean the carbs properly and update the O-rings, adjust the valves, etc. The factory Kawasaki service manual provides a list of basic tasks. Look around on the internet and you can get a free download.
If the exhaust and/or air filter system has been modified there is a good chance the carb jetting is likewise modded. If someone threw some huge jets in the carbs that would explain the poor mileage.
Good luck
If the exhaust and/or air filter system has been modified there is a good chance the carb jetting is likewise modded. If someone threw some huge jets in the carbs that would explain the poor mileage.
Good luck
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
The following user(s) said Thank You: KZShipwreck
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- JR
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Re: Idling speed when warm
18 Mar 2015 16:21
The manual here is not exact for your model but should be good enough for most things.
mbsween.bike-night.com/kz750l3/manual.html
mbsween is a member
I use the manual he linked on the above site and also a Haynes. You probably need to do a really good service on the bike like Nessism says and the manual will help. Do you have original airbox or individual pods ?
Idle speed when warmed up should be about 1200 rpm. You can adjust idle speed with the knob below and between carbs 2 and 3
mbsween is a member
I use the manual he linked on the above site and also a Haynes. You probably need to do a really good service on the bike like Nessism says and the manual will help. Do you have original airbox or individual pods ?
Idle speed when warmed up should be about 1200 rpm. You can adjust idle speed with the knob below and between carbs 2 and 3
1980 kz750E1, Delkevic exhaust
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- Patton
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Re: Idling speed when warm
18 Mar 2015 19:19Hello, KZShipwreck, and WELCOME to KZr!KZShipwreck wrote: Hey Guys,
I am new here and thought I would pick your brains for some advice.
I recently got an 81 KZ750 4 cylinder from a friend. The bike was not running had an oil and a gas leak and he just did not want to deal with it so he gave it to me.
Now after a can of sea foam through the gas the bike runs like a dream. The gas leak I fixed and a bottle of stop leak fixed the oil leak for the short term (I know I will need to deal with that soon)
Recently I noticed that when the bike is cold it idles just fine but after riding a few miles when the engine is nice and hot it idles at around 3000 RPM's and the bike is REALLY heavy on gas I get about 70 miles on the 3 gallon tank before needing to fill up again.
Would you guys happen to know what could be wrong with this bike? Any ideas will be greatly appreciated.

Would sniff-test the crankcase oil and examine its physical condition, being on the lookout for gasoline intrusion into the crankcase, which could explain the oil leakage and excessive fuel consumption.
Good Fortune!

1973 Z1
KZ900 LTD
KZ900 LTD
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- KZShipwreck
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Re: Idling speed when warm
19 Mar 2015 12:51JR wrote: The manual here is not exact for your model but should be good enough for most things. mbsween.bike-night.com/kz750l3/manual.html
mbsween is a member
I use the manual he linked on the above site and also a Haynes. You probably need to do a really good service on the bike like Nessism says and the manual will help. Do you have original airbox or individual pods ?
Idle speed when warmed up should be about 1200 rpm. You can adjust idle speed with the knob below and between carbs 2 and 3
Thanks for the info, I have the pod filters and I did check the carbs yesterday and they looked pretty clean to me. I do think I would need to do some serious maintenance on this bike... lol
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