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Hey Guys,

I have a two bros in the mail and will install when it arives.

Do I need to do anything after installation? There seems to be a bit of banter on resetting the ECU but want to know if this is realy required.
 

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I think that has more to do with a full system and not slip-on only.
 

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^^ Yes, and ^ nope.

Dealer and his wife had slip-ons on for 2 months - a Moriwaki and a Remus. Resetting the ECU made 'a great difference'.


How about running it for a month.

Then resetting the ECU.

Then reporting back to us.

:)

When a computer program has been altered, the computer has to be rebooted right, think of it as the same.
 

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I have heard about 3 different ways to re-set the ECU.

The service guy at my local Honda dealership said that the ECU didn't need to be reset unless you changed parameters of the engine itself, like different sensors, larger injector, or a higher compression ratio. What he recommended doing was installing the exhaust, with the engine completely cooled down, then cutting it on and letting it idle without opening the throttle for 20 minutes, then killing it and letting it cool completely, then re-cranking it and running the piss out of it all the way through its RPM range.

I have heard here that the best approach is to unplug the battery and leave it disconnected for 30 minutes to an hour depending on who is giving the advice.

I have also heard here that the best way to do it is to take it to the dealership and have them do it.

With three very different answers all I am left with is a good number of questions. Which is the proper approach? I would naturally follow the service tech's advice over a bunch of folks on the internet, but I do want to see what the response is here to the tech's advice.

If it matters, I plan on either installing a "megaphone" style exhaust with no muffler (no legal problems in practice where I live- Harleys have straight pipes and they never get any trouble from the local LE) or the new M4 short exhaust. I want to open up the top of my RPM range to help on the highway when moving at highway speeds and needing a little oomph to get around a slow moving car while minimizing my time in his blind-spot.
 

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I have 2Bros installed(from about 20k's) rode to 500k's without reset felt fine torque kicked in when it should etc. Reset at about 500k's (by my Honda dealer at my request, yes watched him do) made no difference that I could tell. I figure if the ECU was not variable to a degree(small degree but slip-on hp diff. is only small) why would it have airflow sensor, exhaust sensor etc if not to be able to adjust on the fly, as I said to a small degree. A full system change on the other hand is a different matter.
Do you need to reset the ECU in a car if u change to high flow muffler, no.
That is my common sense theory anyway I'm not a motor mechanic.
 

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All I did was unplug the battery for 10minutes. Only cause the idea was suggested, I figure unplugging a battery won't do harm, so meh.

The first day of using my Yoshimura-Slip on, I felt it was a bit rough between 4000-6000rpms. Sort of gave a choppy sort of sound, like a Harley, kind of weak on the accelerating too. After awhile it faded to a much smoother sound. Now it performs sweet; nice and smooth from 5000-9000rpm.

The engine does correct itself, I've felt it.
 

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I agree it does adjust itself I only drilled 6 11mm holes in my air filter cover and the change has been noticeable much more rideable in the top end after 500 klms
 

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Why reset the ecu, this is generally why.

EFI ecu;s have a parameter stored in memory called FUEL TRIMS

Now when you reset the ECU you erase these fuel trims, and force the bike to learn new ones.

The are generally IDLE, CRUISE and WOT (Wide open throttle)

So these fuel trims are an easy way for the ECU to change the AFR's by a percentage, My Mitsubishi has them +-15 capable.

So when you let it idle for a bit it will relearn them

When you run it WOT it will learn them

Also not resetting the ECU they will relearn them over pre defined times. But may take a little longer, more so the WOT figure as you may not use it much.
 

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Do you have the pre-defined times for the CBR250 ECU?

My Honda dealer had slip on's on their bikes for over 2 months and they still hadn't adjusted.

Don't know the kms, but they go on a 400km ride every week or two as they sponsor the Thai CBR250 Club.
 

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I'm reporting in after a bit of playing with mine. I pulled the intake cover entirely and pulled the exhaust entirely (header is all that is left, exiting right under my right rear-set). I followed the advice of my service tech and let it idle, killed it, then ran the dogshit out of it, and killed it again, then rode some more at cruising speeds, and killed it yet again.

I noticed the bike pulling much harder at top end rpms with no change in low end performance. So I guess the modification and reset/relearn worked fine.
 

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Seems like the pipe manufactuer would tell you to reset the ECU if it had to be done Im not sure I buy into that idea. Think I will e mail yoshumira and see what they say
 

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You don't need to re set the ECU but it will learn to the pipe quicker if you do. Why not it takes a few min's to dis connect the battery and let it sir for an hour. Not a big deal.
Exactly, Pull the battery before you install it, connect the battery when done. Plenty of time, It wont harm anything at all. (trip meter may be reset)
 

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Do you have the pre-defined times for the CBR250 ECU?


So can anybody get this exact information, without usuallys or normallys?

It would be good to have actual factual information about the parts for this bike. :)

Cheers.
 

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Do you know how to decode raw ECU data? Not many people do. Generally this information isnt really given out, its part of the hard core ecu data, generally found out by people who reverse engineer ECU to be able to re tune stock computers
 

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Nope, don't know how to do any of that. But okay, virtually no one will actually know it.

That won't help these internet debates then. :D
 

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Not until we can connect some sort of OBD2 style data logger, and read the ecu data to see if it does contain normal style fuel trims, then you can from datalogging find the sort of information your after
 
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