KLR 650 Jettings gone wrong? - 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.

 2Likes
 
LinkBack Thread Tools
Old 05-10-2016, 11:29 AM Thread Starter
1st Gear
 
Join Date: May 2016
Posts: 36
KLR 650 Jettings gone wrong?

I bought a new 2016 KLR 650 two months ago. I didn't like the sound so installed Two Bros SR1 exhaust, UNI air filter, KLX needle and jet kit and snorkel removed, AIS system removed.
After lot of testing I have this setup: 145 main and clip on 3rd slot with screw 1.75 turns out. Anything less was way too lean!
It was running good especially i had issues with 1/2 to full throttle (i changed from 142 main to 145 and it worked better ..not sure if i need to go up more).

Yesterday I removed the air box door to see if I need to do L mod. Didn't notice much difference but sound was little better. But after a day of riding it sounds horrible from 1/4- WOT and sometimes it stall the moment i push throttle . Now I don't know if something is wrong with air filter because i ran it with door open or if I burnt glass wool in the exhaust (because i was running it too lean even when i was trying out jettings) and need to repack it? How do I know what exactly is wrong with it?
lonsomecrow is offline  
Sponsored Links
Advertisement
 
Old 05-10-2016, 12:17 PM
Pretty in Pink, dunno why
 
Tom Schmitz's Avatar
 
Join Date: Feb 2009
Location: Redondo Beach
Posts: 7,682
Garage
Those settings, in general, should be good. Slightly rich. perhaps.

Can you describe how you determined that it was too lean at the normal setting of a 142 and the second clip?

Proper setting of the idle mixture screw varies from bike to bike. 1 3/4 turns out is a good starting place, but fiddling needs to be done to get it right. Usually this is done by turning the screw out until the RPM peaks, then bringing it out just a bit further. By doing this what you should have found is the slightly lean spot where RPM is the highest. It will probably stumble a bit when hitting the throttle, so turning it out a bit more richens it up so that it is correct for idle to about 1/4 throttle. You want to play with this to find the spot that has the highest RPM, yet doesn't stumble when the throttle is opened. You may have to go back and forth with the idle mixture an the idle speed screws until you find the happy spot.

But again, what lead you to believe that it was lean at the recommended settings?

Tom
Back2Kawi likes this.

Tom [email protected]

“Some days I feel like playing it smooth. Some days I feel like playing it like a waffle iron.” -Philip Marlowe

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

Sting like a butterfly.
Noli Timere Messorem
Tom Schmitz is online now  
Old 05-10-2016, 12:45 PM Thread Starter
1st Gear
 
Join Date: May 2016
Posts: 36
Quote:
Originally Posted by Tom Schmitz View Post
Those settings, in general, should be good. Slightly rich. perhaps.

Can you describe how you determined that it was too lean at the normal setting of a 142 and the second clip?

Proper setting of the idle mixture screw varies from bike to bike. 1 3/4 turns out is a good starting place, but fiddling needs to be done to get it right. Usually this is done by turning the screw out until the RPM peaks, then bringing it out just a bit further. By doing this what you should have found is the slightly lean spot where RPM is the highest. It will probably stumble a bit when hitting the throttle, so turning it out a bit more richens it up so that it is correct for idle to about 1/4 throttle. You want to play with this to find the spot that has the highest RPM, yet doesn't stumble when the throttle is opened. You may have to go back and forth with the idle mixture an the idle speed screws until you find the happy spot.

But again, what lead you to believe that it was lean at the recommended settings?

Tom
Tom, first of all thanks for your detailed reply!

Two Bros pipe is wide open compare to other exhausts. So I started with the KLX recommended settings first. clip on second slot, 142 main and two turns out. With this setup pickup was not good and lot of decel pooping. So I turned the fuel mix screw out to 2.5 turns and felt little better pickup and popping was almost gone but still not great so turned it out to 3 turns.
At 3 turns out, No popping and pickup was much better and I liked it. But from mid-range throttle position to wide open throttle bike was struggling. Pushing it beyond 60 mph didn't feel good throttle didn't feel smooth at all compared to stock bike with stock pipe. So I tried clip on 3rd slot and notice noticeable difference in mid-range but still it didn't like it when i push it beyond 70 mph lot of vibration and throttle felt heavy. So I changed main to 145 and and it was all good.
But I wasn't sure how to set the fuel screw perfectly and find sweet spot. I tried this trick: increase the idle speed to 3000 and then turn fuel screw in until engine stumbles and then move out until rpm stop rising then stop and turn it 1/4 out and set the idle screw. I noticed when fuel screw was completely closed (all the way in) bike was still running it was surprising because it should die! also when i turn out the fuel screw it dint raise rpm like after 1.5 turns so set it to 1.75 and it felt better at that settings.

So 145 main, KLX needle with clip on 3rd slot and air screw 1.75 turns out was my final setting and it running good even though i dint test ride it beyond 80 mph .

Two days ago I wanted to see if my settings are rich enough and if I need to do L mod. So to verify i opened air box window and rode for a day....didn't feel much difference but sound was better (deeper and throaty) but next day I notice something happened from 1/4 throttle position to wide open, exhaust sounds horrible ..don't know how to explain but sounds like phrrr phhrr and (no thump! ) and also decel popping!

So closed the air box door but still exhaust sound is same and little decel popping. Fuel screw is 2.5 turns out but it some(very little) decel popping is still there !
It runs good but i can feel it that something is not good but cant figure out what.
Dont know what i did by opening air box door or if its something else?!

Thanks
G

Last edited by lonsomecrow; 05-10-2016 at 01:06 PM.
lonsomecrow is offline  
 
Old 05-10-2016, 03:37 PM
Pretty in Pink, dunno why
 
Tom Schmitz's Avatar
 
Join Date: Feb 2009
Location: Redondo Beach
Posts: 7,682
Garage
OK, that's good info that folks can use to help you.

I can't diagnose the problem over the internet, but I can share some stuff that might help your thinking

My bike is set up with a ported head with big valves and I'm running a GSXR750 pipe. That's a pretty wide-open pipe that probably flows similarly to yours.

What I have found is that the generally accepted KLX settings of a 142 main with the needle at the second position gives me a good AFR in the mid 13s range. I could go back and check, but I recall that it was about 13.5:1. I tune with an LM-2 wide-band analyzer. I have the L-Mod done and the snorkel is out.

I did find that I needed to go to a #42 pilot jet. The idle circuit affects running from closed throttle to about 1/4 throttle. I found the additional flow in the exhaust needed a larger pilot to beat the lean pop into submission and give the idle circuit enough adjustment to provide a proper AFR out to 1/4 throttle.

My first thought, since you've gone to a 145 and the third position on the needle, is that you're running too rich. That can be the cause of a 'heavy' throttle feel. The 'snorkel-out, 142, 2nd position, L-mod' set up has worked for me and for many others for a long time. I have run it with stock displacement and with a 685, with stock exhaust, SuperCrapp, and the Gixxer pipe, stock head and modded head. As long as your intake and exhaust flows are balanced (which they really need to be!) it just works. More flow through head and exhaust, as a balanced system will do, simply draws more air, and the tried and true KLX settings manage the AFR. With different engine configurations the AFR changes somewhat, but it always seemed to work and provides a slightly rich AFR which is what you want for good all-around general purpose performance.

Taking the door off should not have upset anything, so don't discard the possibility that something may have happened, coincidentally, in the carb.

I just finished increasing my displacement to 678 with a Wössner high compression piston. Even with the added displacement and the increased compression, I don't expect the tuning to have changed, but I'm going to go through the tuning process anyway.

To do that, I'm going to start with a newly cleaned air filter in place and I'm going to disassemble and clean the carb. I want to start by knowing I have no issues with either.

I'll start at ground zero and reset the idle mixture and then start playing with the needle position. Of course, I will have the advantage of using the analyzer, but the idea is the same. Start from ground zero with a known good filter and clean carb, then go back through the tuning process.

I would suggest that you make sure your filter is newly cleaned and properly oiled, and that you pull the bottom off the carb and clean the main and the emulsifier tube (watch out for the silver needle jet falling out) and blow the passages, at the very least. Do the L-mod (you've increased the potential for exhaust flow; you need to balance that with an increase in potential on the intake side. If you do it by drilling four 1" holes and don't like it, you can use 1" plugs to reverse it.) Then install a #42 pilot (good source is the Harley store), put a clean 142 in, and start over with the needle set at the second position. Reset the idle mixture and see how it goes.

It can be frustrating to have to go back to zero, but it usually works better than trying to work form the middle of a situation and trying to find the solution.

Let us know how it goes; it's how we all learn from others.

Tom

Tom [email protected]

“Some days I feel like playing it smooth. Some days I feel like playing it like a waffle iron.” -Philip Marlowe

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

Sting like a butterfly.
Noli Timere Messorem

Last edited by Tom Schmitz; 05-10-2016 at 03:43 PM.
Tom Schmitz is online now  
Old 05-10-2016, 03:51 PM Thread Starter
1st Gear
 
Join Date: May 2016
Posts: 36
Great Info Tom!

I did start with ground zero and basic setup suggested for KLX. 142 Main, KLX needle on second clip and screw two turns out. But as I mentioned lot popping and not that great pickup made me jump to clip at 3rd and 145 main. But yes I never tried upgrading pilot jet and you have a good point when you say with wide open pipes it needs richer pilot system.

So you are suggesting:
142 main
clip on 2nd slot
Upgrade Pilot to #42
L Mod

I'm going to try this new setup this weekend
lonsomecrow is offline  
Old 05-10-2016, 03:55 PM
Pretty in Pink, dunno why
 
Tom Schmitz's Avatar
 
Join Date: Feb 2009
Location: Redondo Beach
Posts: 7,682
Garage
Yes, and let us know how it works.

Also, since your bike is new, check the torque on the exhaust manifold nuts. They should be at 15 ft-lbs. It would be silly to be chasing a pop that was caused by a leaking exhaust gasket ;^)...

Tom
tjduexjr likes this.

Tom [email protected]

“Some days I feel like playing it smooth. Some days I feel like playing it like a waffle iron.” -Philip Marlowe

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

Sting like a butterfly.
Noli Timere Messorem
Tom Schmitz is online now  
Old 05-10-2016, 03:58 PM Thread Starter
1st Gear
 
Join Date: May 2016
Posts: 36
Also, any good suggestion/tips on how to reset the idle mixture?

Thanks,
G
lonsomecrow is offline  
Old 05-10-2016, 04:06 PM Thread Starter
1st Gear
 
Join Date: May 2016
Posts: 36
Quote:
Originally Posted by Tom Schmitz View Post
Yes, and let us know how it works.

Also, since your bike is new, check the torque on the exhaust manifold nuts. They should be at 15 ft-lbs. It would be silly to be chasing a pop that was caused by a leaking exhaust gasket ;^)...

Tom
Upgrading to Pilot #42 may resolve popping issues but when i go back to clip on second and 142 main I'm afraid my '1/4th to wide open throttle' response will go down. Thats what happened when I was trying with 142 and clip on second slot in the beginning!

Last edited by lonsomecrow; 05-10-2016 at 04:22 PM.
lonsomecrow is offline  
Old 05-10-2016, 04:28 PM Thread Starter
1st Gear
 
Join Date: May 2016
Posts: 36
Also, replying to question you asked me in the beginning "what lead you to believe that it was lean at the recommended settings?"

pipe was turning blue slowly and I suspect its running lean!
lonsomecrow is offline  
Old 05-10-2016, 04:42 PM
Pretty in Pink, dunno why
 
Tom Schmitz's Avatar
 
Join Date: Feb 2009
Location: Redondo Beach
Posts: 7,682
Garage
Quote:
Originally Posted by lonsomecrow View Post
Also, any good suggestion/tips on how to reset the idle mixture?

Thanks,
G
Pretty much the procedure I outlined in my first post. That usually will get is set pretty well.

Tom

Tom [email protected]

“Some days I feel like playing it smooth. Some days I feel like playing it like a waffle iron.” -Philip Marlowe

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

Sting like a butterfly.
Noli Timere Messorem
Tom Schmitz is online now  
Sponsored Links
Advertisement
 
 

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









Thread Tools



Similar Threads
Thread Thread Starter Forum Replies Last Post
mod gone wrong mrxr750 1987 to 2007 Wrenching & Mods 24 05-03-2016 07:32 PM
Why discussions often go wrong Normk The Off Topic Lounge 12 03-13-2015 06:00 AM
something's wrong....but what?! Lizardrider 1987 to 2007 Wrenching & Mods 4 08-07-2012 05:43 PM
OK... what's wrong? Mark B (4) KLR & Other Motorcycle Related Discussion 9 09-13-2010 07:39 PM
Am I in the wrong place? Jjgres KLR & Other Motorcycle Related Discussion 1 12-06-2009 08:15 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