Jetting - Kawasaki KLR 650 Forum
2008+ KLR650 Wrenching & Mod Questions For repair, maintaining or modifying discussions related to the newly updated 2008 and beyond, Generation 2 KLR650 Motorcycle.

 
LinkBack Thread Tools Display Modes
post #1 of 7 Old 06-12-2011, 06:21 PM Thread Starter
Captain
 
Aron31's Avatar
 
Join Date: Apr 2011
Location: Chicago IL
Posts: 298
Jetting

Hi all. Recently installed a fmf exhaust with a power bomb header. I have already done the 22 cent mod with 2 washers, drilled out the slide, turned the air fuel screw to 2 1/2 turns, a k&n air filter, and removed the snorkel. I have stock jetting. I have rode on it for about a week. It feels great but I pulled the plug today and it looks white which indicates that it is running lean. Just wondering what all your reccomendations on jet sizes. Should I just go up 1 size? 2? Just up the main jet or idle as well. The bike idles too high in my opinion... About 1500 rpm. My friends idles at 1000. So just looking for a bit of advice. I'm a newbie when it comes to carb tuning. Thanks.


"If you don't ride in the rain, you don't ride."
"Work to ride and ride to work."
"Accidents hurt - safety doesn't."
Aron31 is offline  
Sponsored Links
Advertisement
 
post #2 of 7 Old 06-12-2011, 06:35 PM
Lieutenant
 
peter650's Avatar
 
Join Date: Jun 2011
Posts: 127
Gday Aron if i was you i would order a klx needle and spacer,and a 148 main jet.Then go from there.How high above sea level are you?At the risk of winding up the K&N fans be very careful going on the dirt with that filter.
peter650 is offline  
post #3 of 7 Old 06-12-2011, 06:51 PM Thread Starter
Captain
 
Aron31's Avatar
 
Join Date: Apr 2011
Location: Chicago IL
Posts: 298
Yeah I'm well aware of the k&n. It came in the bike so I left it. I swap it out when in dirt but my commute is all pavement so 90% of the time I'm fine with it.

I am right at sea level. I would love to try out that set up but am going on a pretty decent length trip leaving tuesday. So I'm hoping to make a fix before then. Maybe a shop in town will have jets in stock that can help it for the trip? The only thing is how big of a. Jet to get. I have the stock 145. Only shop open today in town was Harley and their smallest jet that fit was a 160 which I assumed would be too big of a jump? Would I be correct in that? I was looking for something like a 150-155. Good direction to go or am i wrong?


"If you don't ride in the rain, you don't ride."
"Work to ride and ride to work."
"Accidents hurt - safety doesn't."
Aron31 is offline  
post #4 of 7 Old 06-12-2011, 07:11 PM
Lieutenant
 
peter650's Avatar
 
Join Date: Jun 2011
Posts: 127
If you are a little rich you will be down on power.If you are lean could cost you big $$$.You guys don't have the same fuel as we do so????If your foam filter flows less air you could put that in and do a plug reading.That would give you a idea of how far out your jetting is.The other thing is what have you got to loose by trying the 160,worse thing that can happen is you foul a plug.
peter650 is offline  
post #5 of 7 Old 06-13-2011, 02:28 PM
Pretty in Pink, dunno why
 
Tom Schmitz's Avatar
 
Join Date: Feb 2009
Posts: 4,630
Aron31-

With the snorkel out you should be able to flow more air in, but with the K&N in you should flow less. I don't know if it is a zero-sum game or not, but one might have cancelled out the other.

You've nothing to lose by trying a jet one size larger. Just remember that, with the KLR, there is seldom any reason to go beyond that.

Also remember that the plug reading method is only valid if you are cruising along at mid-throttle or so and chop the ignition and coast to a stop. If you're reading it after going out for for a ride and returning to your shop in a normal fashion the reading may not be true.

Some of the additives and ethanol in gas these days may make for a difficult plug reading. Or so I've heard. Might want to research that a bit.

T

PPMC # 5

'Why' and 'How' are words so important they cannot be too often used. -Napoleon Bonaparte
Tom Schmitz is offline  
post #6 of 7 Old 06-13-2011, 04:16 PM Thread Starter
Captain
 
Aron31's Avatar
 
Join Date: Apr 2011
Location: Chicago IL
Posts: 298
Tom the k&n will flow less than what? Are you saying that a foam will flow better than the k&n?

In any case I went to a 150 from the 145. Ill see how that goes for now. Ill keep my eyes peeled for a 148 jet.


"If you don't ride in the rain, you don't ride."
"Work to ride and ride to work."
"Accidents hurt - safety doesn't."
Aron31 is offline  
post #7 of 7 Old 06-13-2011, 04:24 PM
Pretty in Pink, dunno why
 
Tom Schmitz's Avatar
 
Join Date: Feb 2009
Posts: 4,630
Aron31-

The K&N is reputed not to flow as well as the stock foam filter or a Uni.

K&N have long made advertising hyperbola out of their flow characteristics. They conduct their flow tests at wide-open throttle and compare to stock filters. Not very real world.

150. Jeebus! I have never found anyone who could, with numbers and objective evidence, demonstrate that the KLR could actually run at the correct AFR with much over a stock jet. Honest. Maybe one jet up, but that's about it. Stories abound of "I installed a realy big jet and now I can..." but I've never seen AFR numbers.

OK, I have the snorkel out of the box, the L-Mod done, a 685 kit, ported head with big valves, and a quite free-flowing muffler. I'm using the KLX needle on the second clip with a 142.5 jet.

Now, the KLX has an agressive taper and therefore a comparison of KLX/142.5 jet to stock + two washers/150 jet is not valid, but you can see where I'm going with this...

Somewhere (probably on my other computer) I have a comparison of the taper of the stock needle to the KLX needle. From that we could figure out just how those two scenarios campare.

Do try the 150 and see what happens; the worst that could happen would be an over-rich condition which will show up on a proper plug test. Schnitz is an easy source for jets; their price plus shipping is far less than the average dealership.

Oh, and did you measure the thickness of the washers? I have seen stainless number 4 washers from .010" to .032". Some of them were flat, some were cupped, some had punching burs that increased their effective thickness.

In answer to one of your original questions - you can bring down the idle with the large thumbscrew on the right side of the carb. Turn it anti-clockwise a bit until it's down to your desired 1000 rpm.

T

PPMC # 5

'Why' and 'How' are words so important they cannot be too often used. -Napoleon Bonaparte

Last edited by Tom Schmitz; 06-13-2011 at 04:36 PM.
Tom Schmitz is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Kawasaki KLR 650 Forum 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



Similar Threads
Thread Thread Starter Forum Replies Last Post
KLR Jetting Observations Pistoldave KLR & Other Motorcycle Related Discussion 3 05-02-2011 11:11 PM
Question about the jetting on my KLR patsue 1987 to 2007 Wrenching & Mods 4 10-22-2010 12:58 PM
Why is the air filter left out of jetting threads? john37 1987 to 2007 Wrenching & Mods 6 02-17-2010 12:25 AM
2008 Jetting Question zman 2008+ KLR650 Wrenching & Mod Questions 18 12-22-2009 04:36 PM

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