Dangermouse449
Husqvarna
Pro Class
Disclaimer -
The following worked for my bike.
I am a mechanic, but I'm not a dealer, nor am I Husky trained.
I've gone from 5-10 flameouts per days ride to 'I don't even think about it' still with a factory ecu!
These mods were done after the 'normal' fixes didn't help this bike, & to see if it could be done without an added tuner box.
Edit 1 - Only attempt these mods if you have tried the conventional fixes, Map3, TPS reset etc. and only if you are confidant in your skills working on these expensive electronics.
Forcing the FBW throttle shaft to turn & powering the electrics with plugs disconnected may cause failures, expensive failures. Make sure everything is free of dirt before starting, dirt inside engines is not great.
Edit 2 - It may be, as found on a few of the following riders posts, that the 'after' 2011 bikes might need a TPS reset after the work is completed as detailed here -http://www.cafehusky.com/threads/updated-tps-efi-reset-449-511.28799/
About my bike -
- 2011 TE449 bought new 08/2012.
- Supplied Akro slip-on & jumper plug fitted from new at the dealer.
- Everything else standard until dealer updated mapping during warranty, map unknown at this stage.
EDIT 3 - Australian delivered bikes get an ecu with the same p/no. as Europe, there may be different/better/worse mapping loaded into them over USA/Can ECUs.
- Rode (rather than towed) my bike home from the dealer to put some easy Km's on it,
removed the huge number plate holder & mirrors & whet to the local marked trail to run it in.
(The track has several big hills & some fast open trails.)
- The bike stalled several times & the idle stayed high a couple of times.
- Took the bike home & adjusted the idle screw, still ran the same.
- Took it to the (BMW) dealer, they 'made some adjustments' & said it was fine. (It still played up the same)
- I started to try things myself & make adjustments. Some for the better, some for the worse, over about 6 months.
- I tried all the 'resets', idle screw set at the magic no. of turns etc, no change.
- Just prior to the 12 month warranty expiring, I took it to another local dealer (Berg & Husky) for them to check it out & left it there for a couple of weeks.
I was told they reset the TPS adjustment, reflashed the ECU, swapped ECUs with another bike (which is still in it as the VIN no. on the sticker doesn't match my frame now) Replaced the spark plug, checked the valve clearances, cleaned the earth & terminals etc.
- It ran well for half of the first ride until I stalled it on compression & then had the 'hard to crank over' thing they do, lost the data from the trip meter & clock.
From then on, it returned to flame-outs & erratic idle.
- I replaced the battery with a Lithium one with 90 more cranking amps & the dash now keeps it's memory.
- Went through TPS resets & idle settings again & again, no change.
- I had noticed that if the throttle was just cracked off idle, the revs increased, but it sounded laboured (fuelling not correct) & stumbled.
- I have had a 'dead throttle' condition a few times where I've opened the throttle, the engine run normally (no mis-firing/stumbling etc) but made no power & wouldn't accelerate. Once the throttle was closed, it returned to normal operation again.
- So I put a fair bit of thought into why it flames-out sometimes & not others.
I believe the Fly-By-Wire 2nd throttle doesn't open quick enough at times when you crack the manual throttle, so the ecu sees the throttle open, dumps in the fuel, the FBW plate is still partially closed so not enough air arrives & cough, flameout.
The 'dead throttle' is also the FBW butterfly, it doesn't open at times for some reason, but does not leave a code or flash 'Fail' on the dash.
What can I do about the FBW throttle?
- My original plan was to get the ECU for a TC449 as it doesn't have the second throttle & modify the harness to suit - N.G., too hard.
- You can't remove the FBW throttle set-up. as the ECU 'looks' for the motor & 2nd TPS.
So I stripped the air-cleaner out of the bike & removed the FBW throttle plate & screws from the shaft. (DO NOT drop the screws into the throttle body)
As far as the ECU knows, it is still running the show, all it is doing is turning a shaft & making sure the shaft turned to where it told it to via the 2nd TPS
I still have control of the cable throttle butterfly, and the ecu sees the 1st TPS signals as normal. All good.


What about the hanging idle?
- Obviously my ecu (actually 2 of them) is not capable of making any sort of decisions about idling!
EDIT 4 - My early bike has different ecu/software to 2012 onward bikes, yours may be fine & not need this next mod.
I stripped the throttle cable cover off the throttle body, removed the cable cam from the shaft & removed the arm from the manual throttle section. (This is the arm that the FBW throttle lift & lowers to control idle) Now the ECU can turn the shaft all it wants & not idle the motor high & spit me off into the trees every second time I ride it
I set the idle speed off the brass idle screw similar to the idle knob on the TC , simple!
I have left the brass spacer behind the cable cam & made a plastic guide for the throttle spring to run on (As the arm has a 'cup' for the spring built onto it)
I also took a measurement of the factory gap for the set screw(yellow paint in picture) in case I fell the need to refit it later.

EDIT 5 - 9880sts has posted a pic of his idle arm mod in the thread, he ground off the 'riveted' end of just the roller shaft on the arm, that way the spring cup/guide is all factory, is would be reversible by a small tack of weld if you wish. No need to make a guide this way & safer.
And the dead spot off idle?
I decided to play with the TPS adjustment after finding other Keihin bikes are very picky about the idle output voltages (Most 0.45 -0.6)
It is pretty difficult to get at the pins on the TE449 to actually measure the voltage, so I decided to crack the TPS screw & move it just a bees-whisker in the direction of acceleration of the throttle shaft.
As I moved it slightly, the idle smoothed out & now transitions smoothly to cracked throttle.
Edit 6 - I'm in process of ordering the correct style plugs to make a male/female break-out test lead set & measure the TPS voltage)
Note - I'm unable to get small enough quantities of these plugs (anyone want 500 of them?)
Edit 7 - I've added this here from later in the thread of the the post .....
Over-all, I'm stoked at the changes.
No more driving over the 'bars into that creek bank or log you just tried to pop the front wheel over when it flames out.
No more spearing off the outside of a corner after you expect 450cc engine-braking & get 125 2-stroke engine braking instead.
-Since posting this thread, I've been on probably 20 rides, I can't fault the bike now, I don't even think about the tuning!
I have not bought an aftermarket ecu & had to tune it.
That is one of the fixes for flame-outs available & is plug in fix, but you still have to play with it & tune it. (And it won't cure the hanging throttle or dead throttle issues as it does not control the second throttle shaft)
Hope this helps someone else, as I've mentioned at the start, it worked for my Aust. delivered 2011 model.
It may not do anything for someone else's bike.
If you do go ahead with the mods, please leave some feedback here & let us know what you think -
http://www.cafehusky.com/threads/poll-449-511-efi-butterfly-removal.41619/
The following worked for my bike.
I am a mechanic, but I'm not a dealer, nor am I Husky trained.
I've gone from 5-10 flameouts per days ride to 'I don't even think about it' still with a factory ecu!

These mods were done after the 'normal' fixes didn't help this bike, & to see if it could be done without an added tuner box.
Edit 1 - Only attempt these mods if you have tried the conventional fixes, Map3, TPS reset etc. and only if you are confidant in your skills working on these expensive electronics.
Forcing the FBW throttle shaft to turn & powering the electrics with plugs disconnected may cause failures, expensive failures. Make sure everything is free of dirt before starting, dirt inside engines is not great.
Edit 2 - It may be, as found on a few of the following riders posts, that the 'after' 2011 bikes might need a TPS reset after the work is completed as detailed here -http://www.cafehusky.com/threads/updated-tps-efi-reset-449-511.28799/
About my bike -
- 2011 TE449 bought new 08/2012.
- Supplied Akro slip-on & jumper plug fitted from new at the dealer.
- Everything else standard until dealer updated mapping during warranty, map unknown at this stage.
EDIT 3 - Australian delivered bikes get an ecu with the same p/no. as Europe, there may be different/better/worse mapping loaded into them over USA/Can ECUs.
- Rode (rather than towed) my bike home from the dealer to put some easy Km's on it,
removed the huge number plate holder & mirrors & whet to the local marked trail to run it in.
(The track has several big hills & some fast open trails.)
- The bike stalled several times & the idle stayed high a couple of times.
- Took the bike home & adjusted the idle screw, still ran the same.
- Took it to the (BMW) dealer, they 'made some adjustments' & said it was fine. (It still played up the same)
- I started to try things myself & make adjustments. Some for the better, some for the worse, over about 6 months.
- I tried all the 'resets', idle screw set at the magic no. of turns etc, no change.
- Just prior to the 12 month warranty expiring, I took it to another local dealer (Berg & Husky) for them to check it out & left it there for a couple of weeks.
I was told they reset the TPS adjustment, reflashed the ECU, swapped ECUs with another bike (which is still in it as the VIN no. on the sticker doesn't match my frame now) Replaced the spark plug, checked the valve clearances, cleaned the earth & terminals etc.
- It ran well for half of the first ride until I stalled it on compression & then had the 'hard to crank over' thing they do, lost the data from the trip meter & clock.
From then on, it returned to flame-outs & erratic idle.
- I replaced the battery with a Lithium one with 90 more cranking amps & the dash now keeps it's memory.
- Went through TPS resets & idle settings again & again, no change.
- I had noticed that if the throttle was just cracked off idle, the revs increased, but it sounded laboured (fuelling not correct) & stumbled.
- I have had a 'dead throttle' condition a few times where I've opened the throttle, the engine run normally (no mis-firing/stumbling etc) but made no power & wouldn't accelerate. Once the throttle was closed, it returned to normal operation again.
- So I put a fair bit of thought into why it flames-out sometimes & not others.
I believe the Fly-By-Wire 2nd throttle doesn't open quick enough at times when you crack the manual throttle, so the ecu sees the throttle open, dumps in the fuel, the FBW plate is still partially closed so not enough air arrives & cough, flameout.
The 'dead throttle' is also the FBW butterfly, it doesn't open at times for some reason, but does not leave a code or flash 'Fail' on the dash.
What can I do about the FBW throttle?
- My original plan was to get the ECU for a TC449 as it doesn't have the second throttle & modify the harness to suit - N.G., too hard.
- You can't remove the FBW throttle set-up. as the ECU 'looks' for the motor & 2nd TPS.
So I stripped the air-cleaner out of the bike & removed the FBW throttle plate & screws from the shaft. (DO NOT drop the screws into the throttle body)
As far as the ECU knows, it is still running the show, all it is doing is turning a shaft & making sure the shaft turned to where it told it to via the 2nd TPS

I still have control of the cable throttle butterfly, and the ecu sees the 1st TPS signals as normal. All good.


What about the hanging idle?
- Obviously my ecu (actually 2 of them) is not capable of making any sort of decisions about idling!
EDIT 4 - My early bike has different ecu/software to 2012 onward bikes, yours may be fine & not need this next mod.
I stripped the throttle cable cover off the throttle body, removed the cable cam from the shaft & removed the arm from the manual throttle section. (This is the arm that the FBW throttle lift & lowers to control idle) Now the ECU can turn the shaft all it wants & not idle the motor high & spit me off into the trees every second time I ride it

I have left the brass spacer behind the cable cam & made a plastic guide for the throttle spring to run on (As the arm has a 'cup' for the spring built onto it)
I also took a measurement of the factory gap for the set screw(yellow paint in picture) in case I fell the need to refit it later.

EDIT 5 - 9880sts has posted a pic of his idle arm mod in the thread, he ground off the 'riveted' end of just the roller shaft on the arm, that way the spring cup/guide is all factory, is would be reversible by a small tack of weld if you wish. No need to make a guide this way & safer.
And the dead spot off idle?
I decided to play with the TPS adjustment after finding other Keihin bikes are very picky about the idle output voltages (Most 0.45 -0.6)
It is pretty difficult to get at the pins on the TE449 to actually measure the voltage, so I decided to crack the TPS screw & move it just a bees-whisker in the direction of acceleration of the throttle shaft.
As I moved it slightly, the idle smoothed out & now transitions smoothly to cracked throttle.
Edit 6 - I'm in process of ordering the correct style plugs to make a male/female break-out test lead set & measure the TPS voltage)
Note - I'm unable to get small enough quantities of these plugs (anyone want 500 of them?)
Edit 7 - I've added this here from later in the thread of the the post .....
Some new info on the mods.

In the original post, I mentioned how I have readjusted my primary TPS to richen the maps. (Known as map-shifting)
In the post, I did it by 'ear' finding the smoothest running, turning the TPS as you would a mixture screw on a carb.
I also mentioned that I wanted to get some factory style plugs to make up a test loom & give you all a TPS voltage to aim for, but I had trouble buying small enough quantities of the plugs (less than 500).
Motosportz posted up a link to a guy who supplies KTM tps test looms (also Keihin efi).

I'm happy to report that his test lead is perfect for this & I'll stick the link in the original post.
- http://www.tpstool.com/ (Use the one for EXC models with EFI, plug with 3 pins in a line)
For my bike, the best running without the butterfly in & the Akro slip-on muffler is an idle setting of 0.8v .
This works sweet for my local conditions, no flameouts, nice fat power & can even crack the throttle to full at idle without hesitation.
I'd definitely recommend getting the plug set & try adjusting the settings on your own bike, as I believe it to be half the trouble with stalling issues!!

To use the test lead set -
- Have the ignition (Run switch) turned off (Do NOT turn power on with any plugs disconnected)!
- Disconnect the lower TPS wiring plug from the sensor & connect it to the lead set, plug the other end of the lead set into the TPS sensor.
- Start & run the engine.
- Switch your multimeter to Volts DC (Have it on a setting that will cope with at least 5.0v as there is a signal of 5v in one pin of the plug)
- Place the Earth lead of the multimeter on a good earth on the bike, I chose the cylinder head.
- Place the Positive lead into the pins one at a time until you find the low voltage reading (Less than 1.0 v).
- Compare to the the factory setting which is 0.7v.
- As mentioned above, mine runs sweetest at 0.8v, this is achieved by undoing the locking screw & moving the TPS.
- While you are there, check the 5.0v signal is very close to 5v, mine was 5.01v. (This can indicate power or earth problems to the ECU if incorrect)
** Note. If you move the sensor too far while adjusting, the ecu will cut fuel at idle. If this happens, move it back & begin again **
Over-all, I'm stoked at the changes.
No more driving over the 'bars into that creek bank or log you just tried to pop the front wheel over when it flames out.
No more spearing off the outside of a corner after you expect 450cc engine-braking & get 125 2-stroke engine braking instead.
-Since posting this thread, I've been on probably 20 rides, I can't fault the bike now, I don't even think about the tuning!
I have not bought an aftermarket ecu & had to tune it.
That is one of the fixes for flame-outs available & is plug in fix, but you still have to play with it & tune it. (And it won't cure the hanging throttle or dead throttle issues as it does not control the second throttle shaft)
Hope this helps someone else, as I've mentioned at the start, it worked for my Aust. delivered 2011 model.
It may not do anything for someone else's bike.
If you do go ahead with the mods, please leave some feedback here & let us know what you think -
http://www.cafehusky.com/threads/poll-449-511-efi-butterfly-removal.41619/