2012 500 EXC backfiring on deceleration? - Page 3 - KTM Forums: KTM Motorcycle Forum
Reply
 
LinkBack Thread Tools Display Modes
post #21 of 50 (permalink) Old 04-09-2012, 08:06 PM
Junior Member
 
Join Date: Apr 2012
Posts: 1
Just got a 2012 50 exc and following this thread closely... I want to desmog it but I have a couple of questions: I got a bag of bolts with my kit and I realize that one of them is used to plug the hole from the SAS system - When you remove the catch canister, what do you use to plug the hole where the tube connects to the motor? Does this bolt come with the kit? (What is the use of all of these bolts?).

On a second note, on my first ride, I lost the screen insert on the exhaust... Should I leave as is?

Any help would be greatly appreciated as my dealer is clueless...
bobbike is offline  
Sponsored Links
Advertisement
 
post #22 of 50 (permalink) Old 05-29-2012, 10:51 PM
Member
 
dwigmore's Avatar
 
Join Date: May 2012
Location: Red Deer, AB
Posts: 41
First of all, Wizard/Scott - thanks for the simple to follow instructions! I just finished the "smog mod" tonight, and it couldn't have been easier.

Bobbike, to plug off the small hole on the intake side, I went to the auto parts store and got a rubber cap that is used to plug off extra outlets on a car's vacuum system. As for the screen insert, it may have something to do with the spark arresting system (for preventing forest fires) but shouldn't affect the operation of the bike.
dwigmore is offline  
post #23 of 50 (permalink) Old 08-29-2012, 09:33 AM
Junior Member
 
TerribleOne's Avatar
 
Join Date: Feb 2012
Location: North Jersey
Posts: 3
Quote:
Originally Posted by Wizard64 View Post
Ok, I can feel I might get long winded with this reply for you... but here goes.

(removing SAS valve)

Ok, first you remove the rubber hose from the valve's hose nipple and set the hose somewhere, then I used a 3/4" (or 19mm) "crow's foot" wrench to loosen the aluminum lock-nut (it only needs to be cracked loose, that's all) If you don't have a crow's foot wrench, you might try to reach in with a typical wrench and see if you can grab onto just enough of the locknut to crack it loose. Then I simply rotated the entire valve counter-clockwise to remove it from the engine, but you'll quickly notice that it only rotates about 90 degrees and then the nipple will hit the radiator hose/thermostat housing. I simply pushed that hose/housing away from the valve with the right hand while I rotated the valve with the left hand and it will scrape a little but it does clear and it will continue to spin out all the way after doing that about 3 times. If you don't want to do that you can simply remove the small screws that hold the valve halves together and it will then spin out easily, but really that's not necessary.
Then remember that the bolt that you need to plug the hole where the SAS was removed is a 12mmx1.5 thread. I removed the locknut from the SAS valve and took it with me to Lowes to buy a bolt and quickly found out that Lowes stocks 12mm x 1.25 thread, and 12mm x 1.75 thread, but NOT the 1.5mm thread bolts. So I had to go to a nut & bolt store to buy my bolt.

The SAS valve does the exact same job as the "air pump" does on cars in the '80's and '90's. It allows outside air to be administered into the exhaust near the engine so as the air gets mixed with the exhaust, the 21% of oxygen in the air helps to more completely burn the un-burned hydrocarbons as the air and the unburned HC's travel down the exhaust pipe so that by the time the exhaust exits the pipe there is less un-burned HC's emitted. This system on the KTM acts like an exhaust leak near the exhaust pipe/head flange and that's why it pops in the exhaust during deceleration is because of the cold air coming into the exhaust from the SAS is exactly like an exhaust leak sucking in cold air during deceleration.

The EVAP system isn't allowing cold air into the exhaust, it's allowing outside air directly into the intake port of the cylinder, leaning out the mixture substantially which is why the idle has to be adjusted after removing the EVAP system. I honestly believe that KTM is going to have longevity issues with the EXC engines if they continue to leave the ECM programming the way it presently is now in regards to this EVAP system. It's just simply bad news and not engineered properly I think. After removing both systems I feel soooooooooooooooo much better about my bike's longevity for the long run, and I am also not embarassed anymore by the extreme backfiring or popping.

Scott in Utah

THANK YOU Scott!!!!!!

I have been so extremely frustrated with this bike since the day I bought it, 10 minutes later after following your direction, it runs flawlessly. I am no longer embarrassed to decelerate in front of people. Again, thank you!
TerribleOne is offline  
 
post #24 of 50 (permalink) Old 10-03-2012, 10:54 PM
Junior Member
 
Join Date: Oct 2012
Location: Vallejo,CA
Posts: 9
de-smog kit

Taking your advice I have unplugged the smog and installed the euro map, runs great now. THANK YOU!!!,

Last edited by GoDogGo; 11-07-2012 at 09:39 PM.
GoDogGo is offline  
post #25 of 50 (permalink) Old 10-29-2012, 05:10 PM
Member
 
Join Date: Oct 2012
Location: Rodeo, Ca.
Posts: 30
Good info, just what I was looking for. Wondered about the SAS, had just googled it & found your forum thread. Thanks, just took it off of mine.

Do you have the part # for the plug you installed after removing the SAS unit?

I can do everything through Christ who gives me strength. Phillipians 4:13
'13 KTM 500 EXC, Ascerbis tank, Rekluse clutch
'014 KTM 300 Six Days Edition, Wildcat Motorsports head mod, Rekluse clutch

Last edited by boostracer; 10-29-2012 at 08:18 PM.
boostracer is offline  
post #26 of 50 (permalink) Old 10-30-2012, 06:32 PM
Member
 
Join Date: Oct 2012
Location: Rodeo, Ca.
Posts: 30
Quote:
Originally Posted by GoDogGo View Post
Boostracer, the part number I just asked the parts guy to order me the bolt from a 500 xc-w but just so you know I realized later after re-reading the first posts in this thread that you don't need to plug off the two holes coming off the plastic thing down below like in the vidoe I made, instead you can just remove that little sensor. My bike is still popping though. Seems like I have cut off the extra air the bike was getting and now maybe I'm getting too much fuel. I'm checking with some local KTM gearheads in my area. Someone told me I could get the xc-w black box (brain) and have it re-maped. Apparently the exc black box is set from the factory and can not be re-maped.
Thanks, GoDog, I'll stop by Mach 1 & have him order me a bolt, looks much cleaner. I just shortened & rethreaded an old seat belt bolt I had for now. Sent you a pm. Update: I looked up the part # online, it's item 13 on cylinder head drawing, 78036024000.

I can do everything through Christ who gives me strength. Phillipians 4:13
'13 KTM 500 EXC, Ascerbis tank, Rekluse clutch
'014 KTM 300 Six Days Edition, Wildcat Motorsports head mod, Rekluse clutch

Last edited by boostracer; 10-30-2012 at 08:16 PM. Reason: add info
boostracer is offline  
post #27 of 50 (permalink) Old 10-30-2012, 07:12 PM
Member
 
dwigmore's Avatar
 
Join Date: May 2012
Location: Red Deer, AB
Posts: 41
remapping

Quote:
Originally Posted by GoDogGo View Post
Boostracer, the part number I just asked the parts guy to order me the bolt from a 500 xc-w but just so you know I realized later after re-reading the first posts in this thread that you don't need to plug off the two holes coming off the plastic thing down below like in the vidoe I made, instead you can just remove that little sensor. My bike is still popping though. Seems like I have cut off the extra air the bike was getting and now maybe I'm getting too much fuel. I'm checking with some local KTM gearheads in my area. Someone told me I could get the xc-w black box (brain) and have it re-maped. Apparently the exc black box is set from the factory and can not be re-maped.
I didn't remap my bike when I did this. I see that you removed the "solenoid thing" you had plugged off in the video. I did the same thing - just unplugged the wiring and routed the plug up under the seat. Not sure if you adjusted the setting on your idle speed adjusting screw. If I remember correctly, you have to turn it out (CCW) quite a few times. Maybe that's the problem with yours?

500 EXC - the mirror's there to see if you're still back there!!!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
dwigmore is offline  
post #28 of 50 (permalink) Old 11-01-2012, 12:17 PM
Junior Member
 
Join Date: Oct 2012
Location: Vallejo,CA
Posts: 9
500exc backfire

Quote:
Originally Posted by dwigmore View Post
I didn't remap my bike when I did this. I see that you removed the "solenoid thing" you had plugged off in the video. I did the same thing - just unplugged the wiring and routed the plug up under the seat. Not sure if you adjusted the setting on your idle speed adjusting screw. If I remember correctly, you have to turn it out (CCW) quite a few times. Maybe that's the problem with yours?
Thanks Dwigmore, I will back it out a few more times , I only turned it a little out, it's actually kinda hard to get too. I even noticed it act like a choke if you pull it out like most carbs do but it would be hard to reach it with cloves on and there is no need since the bike fires rite up without it.
GoDogGo is offline  
post #29 of 50 (permalink) Old 11-04-2012, 01:47 PM
Junior Member
 
Join Date: Nov 2012
Posts: 3
2013 500 exc

I am new to this forum. I recently purchased a 2013 500 EXC and I guessing the emissions removal procedure is the same for my bike.
JVP729 is offline  
post #30 of 50 (permalink) Old 11-04-2012, 08:56 PM
Member
 
dwigmore's Avatar
 
Join Date: May 2012
Location: Red Deer, AB
Posts: 41
I would expect so. Check some of the pictures and videos on this thread and you should be able to tell.

500 EXC - the mirror's there to see if you're still back there!!!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
dwigmore is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the KTM Forums: KTM Motorcycle 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



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 Off
Pingbacks are Off
Refbacks are On

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