Poll - 449/511 EFI butterfly removal

As delivered they had a disc blanking off both inlets with a hole drilled in it, restrictor plates.

Yes, the secondary carb was just that, come on just like a secondary throat on a car.
When tuned well it did work, but they dropped it on later models & they ran fine too.
I remember mine REALLY liked fuel, often having to complete a ride on borrowed fuel from my riding buddies (2 stroke) bikes......

Update.

It fell below single figures here this morning, 7deg C, winter is on the way. (I know, nothing to brag about for the US, but hey, it's our winter)

Bike started first crank, no assistance & settled to idle straight away.

DM im quite sure you have map 3.

What exhaust and air filter cover do you have? Is it totally stock? ANY o2 sensor or spark arrestor in the exhaust?

Unmodified airbox(we ride river crossings a bit), standard pipe with just the Husky supplied Akro slip-on.
I have tried O2 fitted & not, no change, so it's in a bag in the house.

Prior to my mods to the EFI, I tried a few runs in closed loop mode with the jumper out & O2 in & could not pick the difference around the streets as it was running then.
Perhaps I had the throttle to wide for it to run in closed loop, it was a short run around streets I know well, but no real change.

Post mods though, holy smoke! A completely different bike, the equal of the 450 & 500 bikes I ride with

Waiting to get the dealer to confirm for sure what has been loaded as I think it is important to the original post so everyone can compare like for like.

Interesting, was that with jumper installed & removed also?

I imagine the o2 is disregarded when the jumper is installed.
Don't know for sure, but makes sense as you could leave the o2 in place & map-switch by running the wires of the jumper to a remote switch.

Removed the butterfly. Does run better but bike still flamed out a few times on my last ride. I have a pcv with burson map and richened lower rpms, tc airbox and fmf powercore 4. Tried the factory map also but think those maps are identical currently.

Will likely need some extra fuel down the bottom as well, mine was by tps adjustment, pcv even easier.
That said, I don't have the powercore system, only an Akro slip-on & standard airbox.
Still worth fine tuning it if you can, the extra low end & mid range are worth the effort I believe.

In the beginning I often mistook my poor clutch work for a flame out.

I retarded timing by about -3 with the PCV in 1250, 1500 and 1750 at 0%, 2% and 5% throttle.

http://www.cafehusky.com/threads/44...ng-with-pcv-at-low-rpm-flameout-theory.41827/

hi there!! Damn, I'm so desperate to have a propper test ride!! Yesterday I just made a short ride, and have to wait 'till weekend to ride it properly...and I have to say that, now it starts better cold or warm, it doesn't matter. Before the mod, when warm engine, I had to twist the throttle a bit to start it, but now, just push the button once and comes alive immediately!!

My opinion about this second BF, can be due to a longer durability of the engine, 'cos the moving parts of the engine wont suffer so much with a smoother movement of them, like piston, valves, cranckshaft, etc...whitout the BF, the response can be more abrupt, so this parts can suffer a bit more wearing out, and that's just my opinión. Wich doesn't mean that I'm going to put the BF back, NO WAY!! I was a bit exceptic about taking it of, beacuse I still have warranty (in Spain is 2 years), but the dealer we have here (Canary Islands), run out of business 4-5 months ago, and now we don't have any Official dealer here, and I spoke with KTM Spain, and man, what a Sh... service, they told me that, if I have any problema with my bike, I have to take it to main Spain, and that means to go by ship there (2 days in it), drive to some Husqvarna dealer there, wich can be 200-300kms from harbour, do the warranty, spend thousends of €€€, and time so, I decide that Fcku the warranty, and of course KTM!!
Sorry if somebody here likes White/blue KTM's, I have nothing agains them, but the service they have SUCKS!! And I can tell, beacuse I was working for them a couple of years, so I really know how they work...

Well, on Sunday, I will give a propper opinion about this BF removal.

Cheers!!

Perhaps the guys making decisions on design and performance were looking at engine braking. I personally hate four stroke engine braking - it is the single thing that kept me from them on my race bike for so many years. I know I am probably in the minority - but the bike has brakes...and I use those. I find the current temperament with it in exactly what I like.

Some crazy guy like me may have made the decision - it seems to be the only benefit (benefit from my perspective) for the design.

I felt the opposite. I think its there to smoothe the power delivery. It made it VERY easy for a dirt noob like me to hillclimb or ride the bike in general on open terrain, whack the throttle wide open and instead of spinning the tire or ripping the wheel of the ground, it would dig, rev, and go! "Dial a ride" I think a fellow rider called it.

Unfortunately on more technical trails/woods it hindered performance, and the massive weight of the bike made me hate life!

On the road (supermoto) I have unlimited traction and need instant response/power thus why I went down the road I did and am trying to harness all I can out of the bike!

I agree as well - I am not a noob on the dirt - but LOVE a finesse approach and the bike hides its weight extremely well. The smooth power, CTS and a trails tire make this a very good single track machine in ridiculously rocky environments.

I can understand that, maybe they did it for that...many times when i was riding, came to my mind that same thoughts, but if i want a bike with no engine brake, i'd get a 2 stroke one... I'm not saying that's a bad idea, but many times I found myself in trouble when I was going fast and a bend was coming, took a gear down, and the bike just went faster...near to crash for that many times...is something you don't expect a 4 stroke engine to do...

It was possibly one of the design briefs.

I'm not judging you, and the choice to buy is yours, but a 'dirt noob' shouldn't buy a 46hp 450 dirtbike unless you're had something else before.
I realise that each person is different & the needs from their bikes is also varied.
Personally, I hated the fact that I couldn't have the power I asked for I paid for that power dammit ha ha.
The other engine braking thing, if mine was consistent, I would have been cool with it being full engine braking 450 style, or none, 2 stroke style. My own bike had a random approach to it and I did end up in the trees on more than one occasion. Lucky not to be hurt....
Now I KNOW it will engine brake, I can carve up to a corner, dive on the brakes, turn & never overrun

There may be fixes available, locally none of the dealers were able to help, but I'm kind of happy, otherwise it wouldn't go like it does now!! Yew.

Tinken, so many people report the dead throttle, my bike has done it since new. Surely we can't all have a faulty #2 TPS???

I find my dead throttle happens mostly when running down hills with little to no throttle, then when I try to blip the throttle to bring the front wheel up over a small wash out I get the dead throttle. My thinking is its something to do with engine braking condition and my accidental rolling a small % of throttle before cracking the throttle quickly.

Anyway back on track, I'll attempt to put my bike on the dyno this weekend and do some back to back runs with and without the #1 butterfly to get a clear understanding of the changes in HP, torque and AFR's.

Very cool - will look forward to seeing those results.