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Discussion Starter #1
Is there really that much different's between K&N, DNA, BMC. For air flow. And if you was to put one in a zx6 would you have to have the ecu changed?
 

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Which ZX6 are we talking, if it's a 2007 onwards, they have lambda sensors and will do some of the correction with the fuel trims in the ecu. As for filter, there is only one choice if you are wanting serious power MWR, got one waiting to go in, once the restrictor comes out in April :)
 

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Discussion Starter #3
Will txt him and find out what year whats a MWR?
 

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Discussion Starter #5
Ive always wondered if changing the air filter, change the way the ecu set's the fuelling setting's on that bike. but wouldn't that be the case in all bike's if you adding more air you have to add more fuel. so you would have to add a power commander to stop things running lean...
 

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Ive always wondered if changing the air filter, change the way the ecu set's the fuelling setting's on that bike. but wouldn't that be the case in all bike's if you adding more air you have to add more fuel. so you would have to add a power commander to stop things running lean...
I would like to know this too... your logic makes sense to me.
 

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MWR make most of the air filters used on the national road racing bikes, and the majority of the BSB and WSBK paddock as well. There is even one team that is sponsored by pipercross and they are using MWR instead. They don't make one for the YZF-R125.

If the ECU has a lambda sensor (sometimes known as an oxygen sensor) in the exhaust, then it can alter the fuel trim to correct the AFR (air to fuel ratio), this will take up small differences from the base map in the ecu. Within the ecu there are two further values, called long term and short term fuel trim, these are correction values derived from the lambda. Bikes running carbs would need rejetting, and bikes with no lambda such as the R125 would need a power commander and a suitable map to correct the fueling. As it's such a small change with a filter, it's within the parameters to be able to correct for the majority of times, things like camshafts and exhaust systems need mapping with something like a power commander. Note I say something like a power commander, there is another choice there, again not available for the R125 sorry guys, the Bazzaz system, cracking bit of kit.
 

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Discussion Starter #8
So he would he need to have a power commander as his got a after market exhaust... But for our bikes if you have stock exhaust and a after market air filter you ok.. With a aftermarket exhaust and stock filter you ok .But if you go with a after market filter and after market exhaust you would need to have a power commander...
 

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I'm running an aftermarket exhaust AND air filter.
Runs fine... but it would probably benefit from me taking it to a dealer to have the o2 levels adjusted.

Could probably do the same with his bike, simply have it adjusted by a dealer...
 

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The CO level adjustment is the equivalent of a long term fuel trim, as the R125 engine does not have a lambda sensor. At standard the R125 runs rich, due to fuelling which is set for poor quality fuels which some parts of the world use.

Bigger bikes like ZX6R's don't have CO adjustments as it has a lambda sensor that adjusts it on the fly. The R125 engine is tuned for reliability and the power levels allowed by law, whereas a 600 supersport is a bit more touchy, and the fueling at the bottom end can soon feel fluffy.
 

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Guys I hope this isn't a total hijack but I have a few questions.

Firstly, I have just fitted a Danmoto Carbon GP exhaust system to my YZFR125, it sounds and looks amazing but it's lost a tiny amount of top end power and backfires like a shotgun! I took it in to Yamaha who said there is NO WAY of adjusting the fueling on the bike except with a power commander / ECU plug in, is this true I thought they could use an FE tool on it?
Secondly, I think an aftermarket air filter will certainly help but am lost as to which one is the forum favourite and am very open to suggestions, bearing in mind the can is a straight through full system and has the connector for the air box hose.
Oh and the videos on YouTube do not give anywhere near the real sound this exhaust makes I think my neighbours sleeping habits are about to change lol
 

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Guys I hope this isn't a total hijack but I have a few questions.

Firstly, I have just fitted a Danmoto Carbon GP exhaust system to my YZFR125, it sounds and looks amazing but it's lost a tiny amount of top end power and backfires like a shotgun! I took it in to Yamaha who said there is NO WAY of adjusting the fueling on the bike except with a power commander / ECU plug in, is this true I thought they could use an FE tool on it?
Secondly, I think an aftermarket air filter will certainly help but am lost as to which one is the forum favourite and am very open to suggestions, bearing in mind the can is a straight through full system and has the connector for the air box hose.
Oh and the videos on YouTube do not give anywhere near the real sound this exhaust makes I think my neighbours sleeping habits are about to change lol

You CAN have the fuel adjusted with the FI tool, but it's a very crude and inaccurate way of adjusting it!
An air filter, WILL give you extra power, but will ALSO require you to have the fuel altered.
 

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So just to clarify... Yamaha CAN adjust the fueling on the bike using a lambda sensor and an FI tool?

Why would they say they can't? Did I just get a slow mechanic?
 

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So just to clarify... Yamaha CAN adjust the fueling on the bike using a lambda sensor and an FI tool?

Why would they say they can't? Did I just get a slow mechanic?
The r125 doesnt have a lambada sensor :) also as above, the r125 runs a bit rich to begin with, so with an air filter and exhaust it should be fine, my r125 still ran excessively rich after a scorp exhaust and k&n filter. You should be fine mate :)
 

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I was reading up on this the other day actually...

Most of the filters available for the R125 don't really increase air flow. They just filter the air better, so less dust and debris enters the engine. It's a common misconception. I would try it and see how it goes.

And I believe Yamaha do have the ability to adjust fueling.
 
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