When to use the "Choke" and how long? - KawiForums - Kawasaki Motorcycle Forums
 
LinkBack Thread Tools Display Modes
post #1 of 10 (permalink) Old 03-21-2010, 02:56 PM Thread Starter
Jr. Member
 
Join Date: Mar 2010
Posts: 74
  
When to use the "Choke" and how long?

I've searched around the net and have gotten mixed results... I was told the choke is bad for the engine and should only be used on extremely cold days.. like 40 degree temp. days. Then I read online that the choke should be used whenever your starting the bike for the first time in a while, no matter the temp. but only keep the choke on till the rpm's start to sky rocket... whats the proper way?
Cjohnson18711 is offline  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old 03-21-2010, 04:14 PM
Lifetime Premium
 
Yuriy's Avatar
 
Join Date: Jan 2010
Location: NJ
Posts: 130
           
I use it on cold days when the bike won't stay on or struggles to keep running because the engine is cold. I try to lower the choke to keep my idle under 3k until it can run with no choke. Once it can run with no choke, I leave it at idle until it's warm.
The choke isn't necessarily bad except that it increases RPM at start which can only be bad because the engine is moving more before oil is able to circulate to lube all the parts.

'01 ZX-6R - Bumble Bee Yellow with DDM Tuning HID Kit
Yuriy is offline  
post #3 of 10 (permalink) Old 03-21-2010, 05:07 PM
Core Member
 
goingtoscotland's Avatar
 
Join Date: Feb 2007
Location: On an intergalactic cruise, in my office
Posts: 28,589
           
Quote:
Originally Posted by Yuriy View Post
The choke isn't necessarily bad except that it increases RPM at start which can only be bad because the engine is moving more before oil is able to circulate to lube all the parts.
actually at idle the oil pump barely works. starting the bike and letting it run until warm at idle is worse for the bike than blipping the throttle(to like 3500 max) a few times when you start your bike and then holding the RPM at around 3000 for a few seconds after that will force the oil pump to work better resulting in better oil flow to the head.

2005 ZX-10R Street and Track Whore

goingtoscotland is offline  
post #4 of 10 (permalink) Old 03-21-2010, 11:18 PM
Intermediate Member
 
racerboy88's Avatar
 
Join Date: Sep 2009
Location: Vancity Home of 2010 Olympics
Posts: 1,577
           
what does the manual say?

Fuelled by rice
racerboy88 is offline  
post #5 of 10 (permalink) Old 03-22-2010, 07:57 AM
Senior Member
 
williamr's Avatar
 
Join Date: Nov 2009
Location: Cheshire, UK
Posts: 5,288
           
Quote:
Originally Posted by goingtoscotland View Post
actually at idle the oil pump barely works. starting the bike and letting it run until warm at idle is worse for the bike than blipping the throttle(to like 3500 max) a few times when you start your bike and then holding the RPM at around 3000 for a few seconds after that will force the oil pump to work better resulting in better oil flow to the head.
Not entirely convinced by that. Anyway, the oil flow to the head is not really very important while the bikes just sitting idling. It does need the pressure built up on the mains and big ends before riding off though. That only takes a few seconds. Letting it warm a bit at idle does minimise the amount of acid from the cold start rich mixture that's blasted past the rings (the seal is less than perfect on a cold motor) to contaminate the oil.

That apart, use as much choke as your bike needs to start and idle, and ease it off as it warms. Too much choke as it warms and you'll find the bike won't rev clean or pull.

Ride around all the time on choke and you'll have a very short lived engine. Use the choke but take it off as the motor warms, and don't do a lot of cold start short trips and it's fine to use. The cold start oil contamination is largely burned off when the oil comes up to full working temperature. That takes about 10 miles or so.

Rob
williamr is offline  
post #6 of 10 (permalink) Old 03-22-2010, 05:30 PM
Core Member
 
goingtoscotland's Avatar
 
Join Date: Feb 2007
Location: On an intergalactic cruise, in my office
Posts: 28,589
           
i'll trust the AMA SBK/WSBK/GP guys. never once seen them just let it idle to warm up.

2005 ZX-10R Street and Track Whore

goingtoscotland is offline  
post #7 of 10 (permalink) Old 03-23-2010, 08:28 AM
Senior Member
 
williamr's Avatar
 
Join Date: Nov 2009
Location: Cheshire, UK
Posts: 5,288
           
I trust my engineering knowledge. These are the same guys who tell you to use the kill switch to turn off the engine?

Rob
williamr is offline  
post #8 of 10 (permalink) Old 03-23-2010, 08:45 AM
KF Exile...
Intermediate Member
 
Jimmi_ZX6R's Avatar
 
Join Date: May 2008
Location: England, UK
Posts: 1,852
           
My understanding is the choke simply does what it "says on the tin" e.g. chokes / cuts the air and thus richens the air/fuel mixture, enabling you to start the bike when cold.

As others have said, I add enough choke to get it started, then adjust it to keep the revs at roughly idle (perhaps slightly higher) until it'll run without.

Running the choke unnecessarily will foul the plugs as per running rich, which is basically what you're doing.

PS I'm not a fan of blipping the throttle on a cold bike myself - it annoys the neighbours. Plus, don't those MotoGP/WSBK boys rebuild their engines after every race?
Jimmi_ZX6R is offline  
post #9 of 10 (permalink) Old 03-23-2010, 03:58 PM
Senior Member
 
williamr's Avatar
 
Join Date: Nov 2009
Location: Cheshire, UK
Posts: 5,288
           
Most race bikes don't like to idle. They're rough as fuck at idle revs and tend to stall. The motors are usually built with a bit more tolerance as well - makes them mechanically noisy but they can stand a bit more abuse cold than most road bikes.

Rob
williamr is offline  
post #10 of 10 (permalink) Old 03-23-2010, 05:23 PM
Core Member
 
goingtoscotland's Avatar
 
Join Date: Feb 2007
Location: On an intergalactic cruise, in my office
Posts: 28,589
           
Quote:
Originally Posted by williamr View Post
I trust my engineering knowledge. These are the same guys who tell you to use the kill switch to turn off the engine?

Rob
never had anyone suggest that actually.

2005 ZX-10R Street and Track Whore

goingtoscotland is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the KawiForums - Kawasaki Motorcycle Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome