Poll - 449/511 EFI butterfly removal

[Cosmokenney]

Just to clarify my post. After removing the butterfly, I'm pretty happy. The throttle is very responsive. It has added a little overall to the power that the JD provided. And the in three hours of normal trail riding I had zero flame outs. Again the only one was at the end of the day when I was playing in first in the trials area.

Rode some more today. I went up to Foresthill and got on some of that super sweet single track. The bike, aside from running a little rough still, ran better than ever. I tweaked the JD much more to my liking and have been amazed at how all uphills are so much easier. I can lighten the front end to get over rocks with a twist of the wrist and can concentrate on riding the technical stuff without worrying about my bike stalling in the middle of it. The combination of the bf removal and the JD has made this bike very enjoyable. Now it's time to do some suspension work... and a rear trials tire. 7602 radiator guards are sitting in the garage and will be going on this week. Then I'm doing spending money on this thing except for consumables.

 

[Dangermouse449]

Ya, I don't understand that effort either. AND, I also could have sworn that, in a different thread, the TC's body was said/shown to be smaller than the TE's. Oh well.

I think I'm correct in remembering, Tinken mentioned the TE body in the pic had been machined out, I think they are the same diameter as original parts. Both are listed as 46mm in the orig sales spec sheets.

 

[Cosmokenney]

I am also having a problem at around 100 mph, but we think it's the silencer.

WTF? Who rides a dirt bike that fast?

 

[Dangermouse449]

Ah yes, I'd forgotten about the fast idle. That would be handy in the cold.
Leaving the idle arm on the primary throttle butterfly will still give you idle up on the TE system though....

On the note of not starting, and I'm not assuming you haven't already tried, but I did find if the TPS was set too far around by the slightest amount, mine won't register as idle.
It would not start until some throttle was added in, then it will start right up, but not continue to run if returned to idle. You did say you had the PCV off when trying...

I have had a little play around to see what works & doesn't since the original post.
I can get a nice smooth idle by a combination of moving the tps- (fuel) & adjusting the brass screw- (air) until the mixture comes good at the right idle speed.
A little bit of trial & error, sure, but the same as tapping in + or - 5% in a map & seeing if it works I guess.

 

[Dangermouse449]

WTF? Who rides a dirt bike that fast?

Desert racers man!
You seen Dakar???

 

[Cosmokenney]

Desert racers man!
You seen Dakar???

Actually, no, I've been obsessed with the likes of erzberg, romainiacs and sea to sky lately.

 

[Big Timmy]

I believe I'll stick with the stock TBI from the BMW. Who knows if I'll keep the second flap or not. I even thought of maybe getting a spare butterfly and drilling a few small air holes in it to see if it would help with the flame outs.

Look, my bike has only flamed out a few times really that pissed me off.

The easiest way to explain it is as follows.

It's not really a big deal in my opinion and where I may have been at the time this happened it could have just as easily happened to a carb equipped bike as well. As the bike literally stalled and came to an abrupt stop on a rocky hill, the clutch was being heavily feathered but it was out and engaged, at a really slow speed. Any disengagement of the clutch at this time would have stopped the bikes forward momentum as well anyway. Which probably would have made it die also because a good handfull and some clutch action would have probably caused a nice loopout. If you know what I'm saying.

I do know though that it is something I feel like its time to recognize that it has flamed out whether I feel like I killed it or not and it's time to try to address the issue.

 

[Dangermouse449]

The TC ecu has all those great things like accel pump and the right fuel mixtures I get from the pcv. But of course you cannot swap ecu's, they made sure of that by making the plugs different.

This is what I REALLY wanted to do, even if I had to find/buy/steal a plug for it & rewire the harness.

(Most of the other plugs are available, they have used Yazaki connectors, maybe they do the multi-pin plugs too.....)

 

[Dangermouse449]

There's another issue with these bikes and their fuel systems. The fuel pumps run all the time, feeding pressure to the regulator and then up to the injector. When the injector meters fuel, it only knows to put in a certain pulse width of fuel and it knows it has 45psi worth of pressure to it. Well, what if it didn't? What if the psi dropped as low as 28psi during hard acceleration?

As far as we know, the pumps are okay, but the seals Husqvarna used were not up to par. I ordered high quality Viton seals to replace the oem ones. I should have an inexpensive kit together soon to fix the pressure drop issues.

That might be where your 100mph problem is...eh?

 

[Dangermouse449]

Ha ha ha, I got hauled over the coals at tech college years ago for running my Datsun rally car up to 85mph on the rollers.
Nearly got kicked out
I just wanted to do some 'real world' runs through 3rd gear! ha ha ha.

 

[Dangermouse449]

But seriously speaking, if you had already lean settings and your fuel pressure dropped in half, you would experience a flame out. The person who did the testing of the fuel pump claims that the fuel pressure drops well beyond normal during the dead throttle times. The new seals are an easy fix, well other than taking out the lower fuel cell.

I hear you about the pressure drop, would not be at all helpful.
All my old flame-outs have been going from idle or very near to it, to cracked throttle of about 50%.
Just used to backfire up the inlet & stop.
The pump pressure can affect all rev ranges i guess, but would be worse at full throttle high rpm (with long pulse widths)

For me, all gone now thankfully.

 

[huskylove]

Here is where I got for the day;

 

[Dangermouse449]

I wish I knew a way to load map3 onto your 449, it would change your entire outlook on it. Someone claimed that they were able to do it in Sweeden I believe or AUS, can't remember which.

I'm not sure map3 isn't already in there.

I've mentioned it before, but the bike has a different ecu in it (from original) that the importer sent to the dealer. (It has 511 written on it in marker pen but a 449 p/no.?!?)
After that lot of work, the bike WAS more responsive for the first ride until the first hard restart after a stall.(and dash/odo reset)
It was almost like it lost all updated data & reset to original (my take on it anyhow)

2 local dealers have mentioned problems with their hst systems atm. (I don't know if it's a licencing thing, or waiting on software, they aren't saying)
Whatever it is, I will get the bike to them & find out one way or the other.

Unfortunately that will be a while, as I fly back out to work for an extended time as we pack up our mining gear to head to another site.....

 

[Isaac]

Hi

Ok, so the top section of the air box can stay in the bike. The rubber air trumpet down onto the throttle body isn't actually joined to the air box. You squeeze the edges in where it goes through the plastic air box & pull it forward into the air box. (When refitting it, you must make 100% sure it has a rubber lip either side of the plastic & is sealed all round)
Removing the butterfly is easy, be careful not to force the shaft to turn any more than needed to undo the screws. Good tip to use a magnetic screwdriver to grab the screws. Also before beginning, clean all dirt from around the area, you don't want that down the inlet.
Zipty can reflash your ecu by mail, but you will be without a bike for a while. You have better maps from new than my older model had, so maybe just moving the tips very slightly will help the lean bottom end maps. I did this with my engine warm & idling, moving the tips the smallest amount, barely noticeable, till the idle smoothed out.
This isn't recommended workshop practice & if you go too far, you may need help from a dealer to set it up again.
Very small adjustments is the key.

Hope this helps make it clearer.

and thanks for the info! I will try this evening to do it and later go for a test ride. About reflashing the ECU at Zipty, I already asked by e-mail to him, and I really don't want to send it there, not that I don't trust about their work, but the post in Spain sucks, and it can be easily lost. And also, I can't be without my beloved bike for so long...

 

[Isaac]

Hi again! I already did it and...that's the way a 450cc should be!!! I'm very sutprised how such a small mod, the bike changed so much!! Very glad I did it, and it took me only half hour to do all the job!! Thanks again for makng me love even more my bike!!

 

[Dangermouse449]

Hi again! I already did it and...that's the way a 450cc should be!!! I'm very sutprised how such a small mod, the bike changed so much!! Very glad I did it, and it took me only half hour to do all the job!! Thanks again for makng me love even more my bike!!

Great to hear! (Add your vote to the poll)
It really does open them up & bring them alive.
I did another 50 km in the bush on my bike yesterday and it is STILL making me smile every time I open the throttle!

Butterfly-free zone!!

 

[Motosportz]

The more positive reviews I read about this the more it makes me feel that obstruction is basically so the ECU can second guess everything for EPA reasons.

 

[Dangermouse449]

The more positive reviews I read about this the more it makes me feel that obstruction is basically so the ECU can second guess everything for EPA reasons.

I still believe it serves no other purpose.
In my opinion it is an electronic version of the two discs in the ports of my old twin carb XR250RE!

 

[Dangermouse449]

If you were a serious motorcycle company making an engine system for racing, you would not deliberately place a restriction on the inlet to limit power.
Anyone racing in this class has doubtless well & truly learnt throttle control.
My thoughts, for what they're worth.

 

[Motosportz]

It is an electronic version of the two discs in the ports of my old twin carb XR250RE!

The difference is the XR has two ports with one BF each right? Thats more of a secondary for increasing velocity on the main circuit then more volume as the secondary opens. This one is a secondary obstrition in the same port.