2011 TE449 Running well with factory EFI system - finally

My own TE never really settled on either providing engine braking, or not. It was inconsistent, so you could not ride accordingly.

I.E. if it ALWAYS engine braked, you could be a bit lazier with the rear brake, if it ALWAYS ran-on like a two-smoker you'd get onto the rear brake earlier.

Mine could never make up it's mind.....I've made that decision for it. Ha ha. (Having normal 450cc engine braking is a big plus on our steep trails also)

Having worked on EFI cars for years, I assumed that this modern, late model bike EFI system would be clever enough to handle opening & closing a butterfly. It can't!

I always wanted to find 'the magic fix' & have it running smooth, idling up cold ect. without pulling things off.

So, in the end I decided to see if it would run properly without the second flap & idle arm.

On my bike, the difference is awesome

Can this be done on TE 310 2009/10?

And so does mine............. end of it.
TC's are not build for On road. So the Emission is not priority number one.

and what about do this mod on a SMR 511?
my TPS make me crazy! :S

Sounds great, but for everyone else hm ? Ah yes , lets buy a Power commander Instead................ or JD Tuner.

And the Joke argument doesn't count. The top Butterfly always stays open at least by about 10-15%. Even the bike is switched off !!


In this treat is quite some Interest....... i wonder why ??????????

If i really want all this what you just wrote Tinken... then i will Install the second Butterfly back in to the Bike.. But no. I am just happy now the way she is and turned out. Couldn't have asked for more and even for free.

Same as my Breather works for me perfect since 1000 km without the catch bottle straight into the Airbox. Thanks for supplying the Valve .

I don't mind going out on a Saturday and riding 4 hrs but covering only 35km's. Not because we have a Smoke on every turn off. We ride some nasty shit here in Victoria AUstralia. Rocks and Logs , creeks , rivers. and Quarry's .

Now i can lift the front easier... just like the Guys on the KATO or BERG... the bikes i started riding with. But i liked the 511 more and bought one.

We have Sections here in CH where you Guys talk about Installing a JD Tuner , Power commander and what the heck else you find on the market. Just because people are not happy with Response and power delivery...
Talking about installing Tc Cam's in Te's and or polishing Intake ... Installing TC throttle bodys......



IMHO.... if you are happy with it............ don't touch it. JUST reat THIS TREAT and forget about it.......
but if you are not happy with your bike a 100% and think about changing something, here are your Option's.


A - you buy a JD tuner or Power thing... 100-400 dollar depending where you buy and live and what you buy.
B - remove just the Top Butterfly , have a go with it... 0$ and if u like it , just leave it. Test for your self.
C - U don't like it, you install Electronic tuner.
D - Buy a different bike.

I think it works as a choke in a different way. It helps the engine to get vacuum when starting as our throttle bodies are huge for the engine size. I think this bike has/had low velocity in the intake or low "vacuum" which could really affect low low rpm throttle response and runnings. So maybe they put the secondary butterfly to smoothe it out so it overcomes this drawback. Remember on old small blocks when you threw a 750 double pumper carb on it thinking it would give you "maximum power" and instead ended up with a bog when you whacked the big carb open? Hence why factory and everyone used a vaccum secondary and a 450cfm carb on the same engine.

Maybe same engineering idea here. Lets use a huge throttle body and then add a flap to smoothe the roll on so you don't end up with no vacuum at low rpm high throttle loads?

Yes? Anyone following me?

I doubt they actually tested it when they were "engineering" it.

You know them german/austrians, they think the engineering is perfect, build and go full on production off an "idea" instead of practical application. Just like how ktm threw the 690's into Baja and found out they needed a few...umm...."fixes" to get them right.

I have a few questions for those of you who removed the FBW butterfly.

1. Are you still running the idle at the recommended 2 1/4 ish turns out on the brass screw, 2000ish rpm? Or did you lower idle after removing the butterfly?
2. Are you experiencing any difficulties starting (cold, hot) without the automatic choke? Is this why you now run the EarthX battery?

I know people complain about losing the smooth power by removing the FBW butterfly... but you don't have to grab a fist full of throttle. Am I missing something? Is it really that much of a difference in power delivery that it can't be managed by throttle control?


I also like the idea of actually having 450 like engine braking introduced by the other part of this mod.

time will tell, just about all the dualsports that are real dirtbikes have
these fueling issues. to think no testing was done or its a stupid design
seems a little much,I am happy with my bike now, and like motosportz,
will probably try it soon just to see. my years of working on bikes 45/
several as a bmw bike mechanic, tell me its not usually a good thing
to remove parts and not replace with something better. most new
bikes come far to lean, and power commander is very common on
all types of bike and atvs. if this mod is good we'll see, the US bikes
come heavily smog proofed and the exhaust is extremely restrictive.
as some have said and myself included they were happy with the
stock bike sorted, but I always want to play, so exhaust, mapping,
PCV ect, ect..we all have different expectations & budgets.
lets remember we bought these boat anchors and help each other
nicely!

Excellent point.

There isn't really a 'choke' on any efi bikes, there is a choke function, and on TEs & TCs that is different.

The efi system adds more fuelling for cold start by mapping, using messages from the coolant temp switch & air temp switch.
The engine then needs more air to go with it.
On a TC, you pull out the fast idle knob, opening up a bypass port to flow air around the butterfly.
On a TE, the idle arm from the FBW throttle lifts the primary butterfly by turning the cam on the shaft.

Pulling out the butterfly from the FBW should play no part what so ever in normal starting.
(I don't live where it snows, so I can't test at those temps, but at all other times mine is fine)

You don't HAVE to modify your own bike this way, but it worked for mine.

1 - Not sure where my brass screw has ended up atm, maybe 3 turns. It works now with the other things I did, that's all i know.

2 - I don't have super cold weather (Min +5 Celsius, but no, starts fine), hot starts, no change at all. - normal.

3 - Fitted my Lithium battery for the times I've stalled it on TDC & the lead/acid battery had trouble winding it over, It used to reset the dash all the time while doing it.

4 -Love the engine braking, the standard TE gearing is a bit tall even in 1st for some of our downhills & it wanted to run away. You can't gear it down with sprockets as then the top speed is too low on the open stuff. Much better now for our stuff.

Tinken -

Do you have a method/modification to increase the engine breaking power on the 449/511? Increased engine breaking has been the part of the this thread I was most interested in. There is kind of a random lag until the engine breaking hits sometimes - adds a bit a drama to a ride for me!

If you have an idea on this subject - please add a topic on your portion on the forum. Thank you.

To me it sounds to be exactly what my bike did from time to time. Maybe 3 or 4 times a ride & not on others at all.....random.
Riding along a trail, cut the throttle & the idle speed is about (no tacho) 4000 rpm, the only way to drop it down at times on my own te449 was to pull in the clutch. TPS & idle screw resets didn't change mine.

No, different system. TE449s & 511s are all on their own.

Perhaps that is why at some point at the dealers it ended up with someone else's ecu in it.....the plot thickens lol
Flashing my own maps in you say.....hmmmm I like the sound of that, if not the expense

I will give my personal review with one small ride in tonight. It seems that this super easy removal of the butterfly has caused the power delivery to be night and day better! It doesn't bog when you get on the gas and it feels smoother. All I've done to my bike so far is put the plug for map 2 in. Haven't messed with the throttle thing but that might not be needed for me.. can't wait to ride more to further my review.

Quick tip.. unscrew the air box and after loosening the clamp by the idle screw for the intake hose you pull from inside the air box and the tube will move out of the way. I was confused until I realizes the air box isn't one piece all the way to the throttle body.

Thanks so much for this great discussion!

Cool, look forward to hearing back how it goes on a longer ride. We could be on a winner by the sound of it

Yes, as 9880sts pointed out mid-post, you can pull the air-boot up into the air-box without removing the whole box as I did in the pics.

I was due for checking my valves at the time I did the mods, so pulled out the whole lot.

It isn't a bad design, although you need to be really particular when you refit the boot into the housing that it has sealed all the way around Or

dirt will kill the engine.