Poll - 449/511 EFI butterfly removal

Ha ha ha. Yes, a bit more power to deal with in a super bike than a little 450/470 single.
Didn't know about the Suzis having them, I knew the Yamis ran them. All Keihin systems I guess,

So glad to be rid of mine, just like any other 450 enduro now, maybe better!

I had lots of flame outs when releasing the throttle to stop and some times when comming out of a stop So i took the emissions canister off and pluged the vacumm line to it, it still happend then i got the FMF power core 4 and it still happend though the bike got better response finally i found and jumped that ECU terminal under the seat to go into racemap 2 and WOW the bike woke up no more flame outs no more tame bike either its perfect now i use to go 79 mph with a 48 tooth rear and with the racemap 2 setting ive gone 89mph but never pushed it faster because of my dirt tires but it could of gone faster gonna go back up to a 51 tooth rear since i dont need to go that fast keeping it on the dirt mostly. needless to say im also not going to touch that butterfly valve.

Been going to the track every monday this last month and I tell you my 511 with all the mods will dust crf450's and ktm's down the straight. With 15/44 gearing if I am ahead they will never catch me. Its FAST. But a heavy no braking under valved piggy. So I keep her on the street and bought a crf450r to race.

Great to hear yours runs well in Map 2, that's why it's in the ECU, to unleash more power.

The butterfly removal won't change the full throttle power, just how the power is delivered after cracking open the throttle.
It will take away the delay in the power building & improve the ridability & response.
It doesn't make more power, but will make it so much easier to loft the front wheel & blast out of corners without the pause that is built into the standard system.
The choice is of course yours, I love mine the way it is.

Would piss me off no end trying to lift the front over a log. Bastard would just stall and Id fall off. Although, I hope I can do it now (I haven't tried it out yet), just have to wait for my stuffed back to get better.

Noob question, is there any instructions here on how to remove the butterfly? Everybody is talking about it and just wanted to give it a try. Just got a 2014 TE511 and I'm trying to get as much info as I can.
Thanks

This is the thread with it in.
I'd only have a go at it if you're fairly handy on the tools.
Have a read through it & decide for yourself.. Take note of the warnings in the thread as well.

Cheers.

http://www.cafehusky.com/threads/2011-te449-running-well-with-factory-efi-system-finally.41069/

Thanks you very much. Looks easy enough to try.

You may need to adjust fuelling as well, one way is detailed in the thread of the post, another is to fit a tuner box like a JD or Power commander.

I was planning on going to Zipty Racing today to get the ECU Map 3. There only about an hour and half from me. I bet they will guide me in the right direction. Thanks again for the all the help.

Map 3 will help yes.

Decided to to go to ZipTy first to do the Map 3. All I can say is WOW and THANK YOU Tinken !!
Anybody who is thinking about this upgrade, DO IT! Its the best 40 dollars you can get for your bike.
I think I'm going to hold off on the butterfly removal as I am so happy with how the bike is running now.

When you get used to it how it is now, you may still want quicker throttle response.
Keep it in mind for later
It is basically the difference between turbo-lag & a NA engine.

Enjoy the 'new ride'.

I just removed the butterfly and it took me about an hour or so. Racemap 2, stock can (still cated) and thankfully I really wasn't having flame out issues. All I can say is what a huge difference. It's so much easier to get the front wheel off the ground.

Just reading an article on the new 2015 WR250F.

It shows some specs in it for the little engine, one which raised a smile is the throttle body size (44mm).

I remember being told after removing the butterfly in my original post that the 449 engine wouldn't take full throttle as the 46mm port would be too big.

Obviously the bikes run fine without the second flap & the little WR250 is running a 44mm body, only 2mm less dia, but 200cc smaller engine.
(Very keen to try this bike btw)

Gotta love EFI if it is well sorted.

PRODUCT CENTRE

17 OCT 2014

Bike: 2015 Yamaha WR250F

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Section: Bikes Post: Alex Gobert
Complete 2015 model Yamaha WR250F information.

Source: Yamaha.

The 2015 Yamaha WR250F, officially unveiled locally on Friday, 17 October, during a presentation at the Australian Motorcycle Grand Prix, is heavily-based upon the championship-winning YZ250F motocross model.
It features the latest revolutionary rearward-slanted, fuel injected, 249cc, DOHC four-stroke engine with four titanium valves, bilateral beam frame, industry-leading KYB SSS suspension, electric starter, aluminum side stand, 18-inch wheel, wide ratio transmission and a sixth gear.
The 2015 WR250F is the perfect bike to tackle the toughest enduros on the planet; the suspension, fuel injection, clutch and engine character have all been carefully chosen to provide the best experience when the riding gets tight and twisty.
The WR250F comes with all the standard features needed to compete and win in enduro events, including a headlight, taillight, skid plate electric radiator fan and enduro computer.
Feature overview:
– All-New for 2015 with a revolutionary rearward-slanted 250cc, liquid-cooled, DOHC four-stroke with four titanium valves based on the 2015 YZ250F, with an added sixth gear and wide ratio transmission, among other modifications, make it perfect for enduro competition.
– Nearly the same bilateral beam frame that is found on the championship winning YZ250F is used on the WR250F. It places the engine and fuel tank close to the center mass of the bike for extremely light and nimble handling character.
– A Keihin 44mm throttle body fuel injection system is tuned for enduro riding ensures smooth throttle response and easy starting in nearly all conditions. Plus the electric start button reduces rider fatigue.

well after riding round the flame outs for the last 5000 miles, I pulled the butterfly, installed a tc air box lid and an iridium plug,
Today I did my normal 80 mile route that would include at least 10 flameouts,and am pleased to say not one all day.
The power is certainly much different now, not so linear now but a big snap of power instead which suits my style.
Just waiting for the powercommander to come back from dynojet so i can start to have some real fun

I've got to get one of these for, um, my son.

Lucky.....um, son!

I'm actually looking at one for myself in the hope that Athena will release a 290 kit for the new reverse engine.
I think it would be the perfect bike for our areas where the tracks are a little tighter & more technical.

It is down to this one, the 2015 Suzuki RMX450 enduro & the 2015 Shreco 450 sef-r.
Once I get a ride on all three I'll make the decission.