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Discussion Starter #1
So with a full system exhaust from Yoshimura would the ecu have to be reset or is a tune of some sort required? I do not want to lay down some cash and not know for sure what exactly would be required. I plan to do a simple bolt on and battery disconnect for the ecu reset.. What do you guys think?
 

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Where do you notice the increase? Is it more of a top end (as I would suspect given a standard compression ration naturally aspirated engine with an opened exhaust) or is it a lower to mid end increase?
 

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Has it been established that disonnecting the battery really works to reset the ecu when putting on a bolt on exhaust? How long does it need to be disconnected?
 

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Nothing more than bolting it on required. You will feel it right away, and get's better over the next couple days.
I've a thread called something like 'Make sure to do if changing the exhaust pipe'.

Long story short, I had my full system on for 3 days, my Honda dealer had his Remus on for more than 2 months, his wife has a moriwaki on hers for 2 months plus too. Resetting the ECU made a great difference to all the bikes.
 

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Discussion Starter #6
I would assume that the battery would need to be disconnected for at least 30 minutes. I am drawing from my experience with trucks in the past to determine that. This is not a scientific method by any measure. If I can find the proper procedure in step by step format from a service manual then I will do it that way...
 

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My Honda dealer was going to video log how to do it as they did it to a number of bikes with aftermarket systems, the Honda big boys quickly told him not - it's company business.

It's in the shop manual spread out over about 3 pages I think.
 

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My Honda dealer was going to video log how to do it as they did it to a number of bikes with aftermarket systems, the Honda big boys quickly told him not - it's company business.

It's in the shop manual spread out over about 3 pages I think.
I need to find a shop manual then.
 

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:)I have been on the phone with 3 mfg of FULL EXHAUST SYSYEM for the CBR250R , they all say that you DO NOT have to change the ECU/ECM for the street,but you may want to change the fuel mapping if you are going to race the bike or use it for a track day bike:eek:
 

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^ They're incorrect then.

btw, the dealer has a rough 3 video lesson on youtube about how to reset the ECM.

Think his name on youtube is 'brianabo1'. Or just search for 'Namban exhaust cbr250r' and he'll be the poster of that video.
 

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3 Part ECM Reset, Part 1 (2 and 3 should be links)


It's not exactly clear which wires to jump on the coolant sensor from the video.
 

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Stock ECU doesn't have the ability to automatically change too much.

If aftermarket pipe company are saying it doesn't need to be done it's probably to protect sales, as it's an added cost/time for the customer.

Honda dealer and his wife (She's the owner, he's the manager) and their staff all noticed the difference after having their after market pipes on for 2 months. (Remus and Moriwaki pipes)
 

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so I have watched the videos uploaded by redline's dealer. (btw thank him for me next time you see him) I found the coolant sensor and ecu; the only problem is I can't figure out how to take the tail apart to get to the wire loom that runs to the tail light. anyone have some tips on getting all that plastic off?
 

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Handy post for the buffs and tuners here.

I doubt I will ever change from the stock standard setup..like the quiet exhaust etc., but for interest I would like to understand a bit more of the how the ECM modulates fuel and spark beyond the basics. Seems there is not a great deal of info explaining the full story..as yet. For instance, from what I have read, it appears that the O2 sensor only influences when the PAIR solenoid is energised. I would have thought it would also be used to influence fuel delivery too at times. But with the economy its gets, maybe it doesn't need to be that smart.

Does anyone know if the factory workshop manual has the full story? For those who are into the geeky side of things!:D
 

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Basic EFI systems have 2 modes, Open loop and Closed loop.

In closed loop the ECU will control fuel to 14.7:1 mix, this is used for idle and all low load applications.

Once you hit a set of defined figures, generally load and throttle position,it will then operate in open loop mode, and will follow a 2d or 3d graph of air fuel ratios for load and RPM, then give the fuels thats programmed for.

When you tune a car, you edit that OPEN loop mode as thats where the fuel can go rich or lean, and you can change it.

As I mentioned in another post they also have fuel trim setting where it will trim the fuel for different mode like idle, cruise and Wide Open Throttle, this is what gets learnt when you mod stuff and is in a soft RAM, when you reset the ECU you force those figures to reset and get re learnt.

They are generally around 15% +-
 

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Probably bit of a noob question, when you reset the ECU As shown in the Video, Do you have to rev the guts out of your bike like they do in the video?
 

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I'm not too sure, but doing that is a Thai trait. :rolleyes:

Whenever you get anything done, even a puncture fix, they'll want to redline it in front of you when you go to pick it up. :(
 

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I'm not too sure, but doing that is a Thai trait. :rolleyes:

Whenever you get anything done, even a puncture fix, they'll want to redline it in front of you when you go to pick it up. :(
haha...yeah, they seem to love the rev limiter!...hope they don't bypass that.
 

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has anyone done this themselves yet? how did you get to the connector by the tail light?
 
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