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A Little Deeper Into Pair.


coderighter

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So 4 years ago now, I had plugged my PAIR at the valve covers in order to install Autotune. Shortly after that, I bought block plates but just last weekend got around to installing them.

I installed the rear plate, no big deal, but when I got to the front I noticed that one of the reed valves had been leaking. The reeds 'close' against a layer of rubber that's molded around the plate opening. It would seem at some point the rubber had gotten 'heated', and was no longer flat causing a leak.

It would seem to me, the purpose of the reed valve is prevent exhaust from traveling between cylinders and/or back to the airbox. Because I had the valve cover port plugged, the exhaust couldn't get back to the airbox but I wonder what problems can come from a port being open between cylinders. Well, I guess since one valve seemed fine, I had flow one way only.

Today, I rode it to work and I swear it's never ran smoother. I'm not sure if it's because I fixed the leak or if it was just a really good day for the engine. You know, every engine runs a little different depending on condiitons of the day.

Thoughts?

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The reed tubes normally feed the exhaust with extra air, it simply get sucked in there, this to fool sniffers of the CO2-maffia that the bike is cleaner then it really is.

And it's coming from the airbox via the pairing-valve.

In theory if the pairing-vavle is open and the tubes are leaking (not airtight) you could suck dirty air into the air intake of the cylinders.

That would be bad as it bypasses the air-filter.

I suggest you remove the paring-valve and the 3 tubes that connect to it, and simply block the connection at the airbox.

As you do use blocking plates, there is no need to keep the system installed and can be removed in total.

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The reed tubes normally feed the exhaust with extra air, it simply get sucked in there, this to fool sniffers of the CO2-maffia that the bike is cleaner then it really is.

And it's coming from the airbox via the pairing-valve.

In theory if the pairing-vavle is open and the tubes are leaking (not airtight) you could suck dirty air into the air intake of the cylinders.

That would be bad as it bypasses the air-filter.

I suggest you remove the paring-valve and the 3 tubes that connect to it, and simply block the connection at the airbox.

As you do use blocking plates, there is no need to keep the system installed and can be removed in total.

While there is a external valve with the 3 hoses hanging off the airbox, there are also 2 reed check valves in each valve cover, one for each cylinder. Those are the valves in question, not the external one.

Side note The air provided by PAIR to the exhaust is there to provide oxygen in hopes of burning any left over hyrocarbons as the exhaust is leaving the cylinder. The purpose is to reduce hydrocarbon emission during warm-up. It also helps to get the CAT heated up faster, again to reduce hydrocarbon emissions.

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The 2 tubes that goto the cylinders are to give air under the cover, you should not block those, but they have to be good.

So if they leak you better replace them, as it could lead to dirt in your oil.

As for the burning of leftovers, that is a nice story to hide their CO2 real emission.

It also messes with your CO2 sensor making the computer believe the mixture isn't right, won't show with the standard exhaust but does when you have an after market.

Sorry to say, but it does nothing but fool the CO2 sniffers.

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I presume you mean the tubes coming from the airbox and goto the cylinder-covers.

They are there to let (clean) air in and out of the oil-circuit.

If those are leaking they could (in theory) put dirt in your oil.

I assume you mean those, else show a picture of the tubes you are talking about.

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I presume you mean the tubes coming from the airbox and goto the cylinder-covers.

They are there to let (clean) air in and out of the oil-circuit.

If those are leaking they could (in theory) put dirt in your oil.

I assume you mean those, else show a picture of the tubes you are talking about.

I never said anything about 'tubes'.

Air in the oil-circuit?!?

I would really suggest you read through this -

http://www.autoshop101.com/forms/h65.pdf

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The pairing system on a VFR (and other Injection bikes) consist only of 3 tubes and a valve.

The only thing is does is put clean air in the exhaust at low RPM to fool the sniffers.

It's no more complicated then this:

pairstock.jpg

It can simply be removed in total and blocked at 3 points, 2x at the exhaust where you put the blocking plates.

And 1x at the airbox before it goes to the pairing-valve.

As for leaking a bit near the exhaust, that could happen, as it gets hot there, it's the exhaust.

However I would close it, use some closing material to seal it else the O2 sensor still (may) think the mixture isn't right.

The pairing system isn't useful, it's just a major fraud to pass the CO2-maffia rules, nothing more.

As you can't optimize a bike that has optimal burning of fuels, that generates CO2 as optimal combustion is maximal CO2 (it's a bit more complicated but still).

However the CO2-maffia turned CO2 into a bad thing, as such you need more O2 in your gases, what better way to do it then simply inject O2 in the exhaust itself?

And because they do it before the cat it mixes perfectly and the rules of less CO2 compared to O2 is met.

It really has no other meaning then that.

Have fun: http://www.engineeringtoolbox.com/boiler-combustion-efficiency-d_271.html

The real bad gas is CO, that kills people, but they never talk about that.

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The pairing system on a VFR (and other Injection bikes) consist only of 3 tubes and a valve.

The only thing is does is put clean air in the exhaust at low RPM to fool the sniffers.

It's no more complicated then this:

pairstock.jpg

It can simply be removed in total and blocked at 3 points, 2x at the exhaust where you put the blocking plates.

And 1x at the airbox before it goes to the pairing-valve.

As for leaking a bit near the exhaust, that could happen, as it gets hot there, it's the exhaust.

However I would close it, use some closing material to seal it else the O2 sensor still (may) think the mixture isn't right.

The pairing system isn't useful, it's just a major fraud to pass the CO2-maffia rules, nothing more.

As you can't optimize a bike that has optimal burning of fuels, that generates CO2 as optimal combustion is maximal CO2 (it's a bit more complicated but still).

However the CO2-maffia turned CO2 into a bad thing, as such you need more O2 in your gases, what better way to do it then simply inject O2 in the exhaust itself?

And because they do it before the cat it mixes perfectly and the rules of less CO2 compared to O2 is met.

It really has no other meaning then that.

Have fun: http://www.engineeringtoolbox.com/boiler-combustion-efficiency-d_271.html

The real bad gas is CO, that kills people, but they never talk about that.

That is the most misguided and false explanation of the functional workings of the PAIR system I've ever seen. If all that was needed is to add air to the exhaust, there would be much easier and cheaper ways of doing that.

Please go back read this link, I beg you.

http://www.autoshop101.com/forms/h65.pdf

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No there are no easier ways to do it, as you have to control the exhaust to to make it run well.

But hey, don't believe me, trust your autoshop stuff, I don't care.

Or do you believe the flapper has a function too? It's just to pass the noise rules at about 5000 RPM.

Heck in Germany Porsche called their 1st gear "Gelände" meaning terrain-gear, just to make sure they where able to pass sound tests in third and not the second gear as everybody else.

Do you really believe pairing is good for the environment? I bet you think solar-panels are good too right?

It's just a fraud to pass regulations, nothing else. But hey, everybody is free to believe what they want.

If you think it's a good system, well why do you block it???

BTW carburator cars have cats for years and years, they never needed pairing.

Yet currently the injection engines need it, while their combustion is far better then ever before.

It's fraud.

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To help you a bit:

http://www.moccsplace.com/images/pair/pair1.htm

http://johnny.chadda.se/article/pair-and-flapper-mod-with-bonus-snorkel-mod-for-vfr/

http://www.m109riders.com/forums/showthread.php?t=68735

http://tech.bareasschoppers.com/engine/vtx-1800-desmog/

Everybody is saying the system is rubbish and not doing anything but make sure it meets te sniffers demands.

Want me to give to a load more pages?

The pairing and flapper serve no purpose, none at all. Some do explain it a bit like your believe, but all remove it.

If you talk to bike-engineers, they all tell you it's useless crap.

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No there are no easier ways to do it, as you have to control the exhaust to to make it run well.

But hey, don't believe me, trust your autoshop stuff, I don't care.

Or do you believe the flapper has a function too? It's just to pass the noise rules at about 5000 RPM.

Heck in Germany Porsche called their 1st gear "Gelände" meaning terrain-gear, just to make sure they where able to pass sound tests in third and not the second gear as everybody else.

Do you really believe pairing is good for the environment? I bet you think solar-panels are good too right?

It's just a fraud to pass regulations, nothing else. But hey, everybody is free to believe what they want.

If you think it's a good system, well why do you block it???

BTW carburator cars have cats for years and years, they never needed pairing.

Yet currently the injection engines need it, while their combustion is far better then ever before.

It's fraud.

Hmm... My 2008 BMW (very much fuel injection) doesn't have any air injection while my 1997 BMW (also fuel injected) does have a air injection. Now why would that be?

I didn't say it was a good or bad system. Actually, if it helps reduce emissions, I have no problem with that as long as it doesn't-

A) Hurt gas mileage

B) Hurt performance

C) Cause undo wear on the engine

D) Fail, causing A,B, or C

The PAIR system doesn't cause A,B, or C.

The reason I took mine off was because I was misinformed, much like you. I was told it had to be disabled because it would interfere with my Autotune because the added air would throw off the O2 sensor. Turns out, that's wrong.

The statement below is not a guess, or a theory, it's fact. I've actually gotten out a multimeter and saw this with my own eyes, on my bike.

The ECU only only operates the solenoid air valve when-

1. The throttle is closed.

2. The coolant temp is below 168-ish

Unless those 2 items are true, the valve is closed, meaning that PAIR doesn't effect A,B, or C.

Now, since mine is already disabled, I see no reason to re-enable the system because of 'D'. That being said I would not disable just for the sake of 'D'.

So.... The question that started this all, was that even thou I had removed all the hoses, the solenoid valve, and plugged the ports on top of the valve covers and air box, it did not prevent 'D' from happening because one of the reed valves under the port on the valve cover failed causing an exhaust leak in between cylinders. Does this leak cause a big problem? Did the valve seat 'melt' because the PAIR was disabled stopping any air flow ever? Is the only true way to prevent failure removing the reed valve and blocking the ports?

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Another function of the PAIR is to get the cat up to operating temperature. Pretty sure they're not heated separately on these bikes, so they rely on the heat of combustion in the pipe to get up to temp. I've noticed that the ECU dumps extra fuel at idle, which is when the PAIR is passing fresh air in. The extra air and fuel mix to heat the cat up to operating temp, which does more for emissions than the PAIR alone would.

Old cars didn't have them, but they didn't work very well either. The 80s weren't exactly noted for performance... :o(

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PAIR was always explained as a secondary system to introduce oxygen downstream of the exhaust valve to continue combustion of any unburnt gasses (mostly caused by on-choke rich mixture state) in the exhaust manifold. It is that simple and not some big mysterious "fraud" propagated by Honda to "fool the sniffers" and force us to carry that extra couple of pounds of equipment on our bikes....otherwise, believe me, many Honda owners over here would have sued Honda years ago for "fraud".....

.. And the so called "sniffers" can't be easily fooled anyway.......

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To help you a bit:

http://www.moccsplace.com/images/pair/pair1.htm

http://johnny.chadda.se/article/pair-and-flapper-mod-with-bonus-snorkel-mod-for-vfr/

http://www.m109riders.com/forums/showthread.php?t=68735

http://tech.bareasschoppers.com/engine/vtx-1800-desmog/

Everybody is saying the system is rubbish and not doing anything but make sure it meets te sniffers demands.

Want me to give to a load more pages?

The pairing and flapper serve no purpose, none at all. Some do explain it a bit like your believe, but all remove it.

If you talk to bike-engineers, they all tell you it's useless crap.

Blogs and forums, not technical documents.

Tell you what, you're listed as a Electronic Engineeer, do this.

Apply 12v to the PAIR valve, you'll notice it allows air to pass, remove the 12v and the valve will block the air flow. Now we know that to operate the PAIR, the ECU supplies 12v to the valve.

Now start the bike cold and measure the voltage at the PAIR connector on the bike and you'll notice 12v present, meaning PAIR is active. Now keep measuring while slowing taking the throttle off idle and you'll notice as soon as you get off the throttle stop, the voltage goes to zero. If the valve is closed when the throttle is off idle, then the PAIR system as no effect while the bike is under power, blocking the PAIR will make no difference since it's 'blocked' by the valve anyway

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So.... The question that started this all, was that even thou I had removed all the hoses, the solenoid valve, and plugged the ports on top of the valve covers and air box, it did not prevent 'D' from happening because one of the reed valves under the port on the valve cover failed causing an exhaust leak in between cylinders. Does this leak cause a big problem? Did the valve seat 'melt' because the PAIR was disabled stopping any air flow ever? Is the only true way to prevent failure removing the reed valve and blocking the ports?

I got it now, sorry was looking at a wrong angle related to your problem.

I have done some digging and I think the reason it's melting is because one of your blocking plates is leaking.

Because if it is leaking gasses will pass from the exhaust and heat up the aluminum plate, so hot that it could melt the reed.

That means your blocking isn't done properly, ergo you have to seal the leak.

When there is no leak the plate isn't heating up and the reed shouldn't be heated or do anything at all.

In fact, when you mounted the plates, you could have removed the reed in total in my opinion, but I just did the marble trick.

The melting isn't caused by the disabling of the pair system, but by a failure (leak) of your attempt to disable the system.

That is what I found by reading others that report the same happening and it looks to be the case.

As for the effect under power, the paring-system has a major effect under power, but you won't notice with a stock exhaust as it masks it.

The riding comfort between 3000~4000rpm completely changed after blocking it.

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With the cat con up to temp and a stock bike, pair activated... at idle, my 6.5 gen emits 0.05 CO2... the permisible level is 0.5... my catless 5th gen ('98) gives out 2.5... that's a 50000% difference... my buddy's 6th gen with Pair and Flapper disabled and O2 sensors switched over (apparently installed switched around at the factory), runs smooth but it is yet to bee seen that his emissions will pass roadworthy restrictions.

Sorry I know it's off topic... this thread is about why your reed valve casing melted, I guess we should leave the discussion regarding PAIR and such for the designated threads.

I think the question is whether or not it is not adviseable to remove the reed valves as regards the risk of getting cross-over leaking between cylinders, just as Coderighter is pointing out... thinking out loud, cylinder 1 and 3 in one bank and 2 and 4 in the other, do not have their exhaust ports open simultaneously... so exhaust from cylinder 1 could hang out in the section common to both cylinders upstream of the reed valve (one reed valve for both cylinders right?)... but I think you need not be concerned CR, as the exhaust port of the other cylinder would be closed, would it not? Not posible for those gases lingering in the comunal zone to enter the other cylinder, they will get forced through the reed valve when the other exhaust port opens and new emissions issue forth... neither do the cylinders in the one common cylinder bank fire one immediately after the other... also if I understand correctly and as an estension of the aforementioned, the reed valve doesn't separate one exhaust port from the other, but there is a "meeting of the ways" just prior to reaching the valve. Right?

Yet, if as Bassie sates, your block off plate has a leak, this would allow even fresher 02 on top of the reed valve... causing combustion on the upper side of the reed valve (when PAIR allows this to take place from underneath the reed valve)... this would definitely deform the rubber part as it's not designed for the combustion to come down from on top, but up from below...

Don't know if I'm making myself clear or not.

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It's my opinion that the reed is only there to prevent the pairing-tube to push exhaust-gases back into the airbox.

But because the pairing-blocking there is no function for the reeds anymore.

As such I believe it can be removed in total, reeds as well as the plumbing.

However, I didn't though about O2 being sucked in because of a leak, I thought of gases being pushed out and overheat the sealing.

Either way, it should not leak.

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So.... The question that started this all, was that even thou I had removed all the hoses, the solenoid valve, and plugged the ports on top of the valve covers and air box, it did not prevent 'D' from happening because one of the reed valves under the port on the valve cover failed causing an exhaust leak in between cylinders. Does this leak cause a big problem? Did the valve seat 'melt' because the PAIR was disabled stopping any air flow ever? Is the only true way to prevent failure removing the reed valve and blocking the ports?

I got it now, sorry was looking at a wrong angle related to your problem.

I have done some digging and I think the reason it's melting is because one of your blocking plates is leaking.

Because if it is leaking gasses will pass from the exhaust and heat up the aluminum plate, so hot that it could melt the reed.

That means your blocking isn't done properly, ergo you have to seal the leak.

When there is no leak the plate isn't heating up and the reed shouldn't be heated or do anything at all.

In fact, when you mounted the plates, you could have removed the reed in total in my opinion, but I just did the marble trick.

The melting isn't caused by the disabling of the pair system, but by a failure (leak) of your attempt to disable the system.

That is what I found by reading others that report the same happening and it looks to be the case.

As for the effect under power, the paring-system has a major effect under power, but you won't notice with a stock exhaust as it masks it.

The riding comfort between 3000~4000rpm completely changed after blocking it.

Actually, for the last 4 years I have not had the blocking plate installed, I had disabled the PAIR by removing all hoses and capping the ports on top of the valve covers and, of coarse, the air box.

It was when I went to install the blocking plate last weekend that I found the melted valve seat.

Since I disabled the PAIR back when the bike had less than 500 mile, I have to believe it happened while it's been disabled.

I'm pretty sure that the reed valves are there to keep the cylinders isolated. If the concern was stopping reverse flow to the air box, only one reed valve would have been required right at the port it's self. Without the isolation, there would be some kind of twisted EGR system.

I've seen stories where people either installed the blocking plates with reeds still mounted on the plate which causes a leak because the screws are too tall and does not allow the plate to seal. I've also seen where they leave the reed plates out because the screws interfere and this opens a large section under the plate that 'links' the 2 cylinders together. The screws must be removed along with the reeds and the reed plate reinstalled.

So..... Did disabling by plugging cause the melt or is this just something that needs to be checked every now and then, whether you PAIR is disabled or not. Are blocking plates the only real way to disable for those that choose to disable?

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The valve reeds don't keep the cylinders insulated, why would they?

They are there to block the combusted gases to get back into the airbox.

As the exhaust is combined at the cat anyway, why insulate them?

Each cylinder has it's own outlet valves and they are closed on turn anyway.

Have you noticed this? There is no air-pump to let air flow from the airbox to the reeds.

Also the tubes are not made for high temps or pressure.

It's my opinion that the combusted air is pushed out by the cylinder, then reach the reed (that closes because of the pressure) it follows it path to the cat.

However, because of the combined pipes at the cat, the other pipe to cylinder no2 is getting under-pressure, so it sucks in air from the pairing and that waits there until the outlet-vavle opens to press combusted air out.

That mixture goes in the direction of the reed (that closes on it's turn) and follows it's way to the cat.

Then reed 1 opens and air is sucked into exhaust 1 etc...

I really believe your blocking (either plates or before) was leaking hot combustion air into the pairing-system or passing your reed somehow and made it melt.

Maybe the reed on 1 cylinder was never placed properly and melted because of passing gases.

So in my opinion the reed malfunctioned somehow even before the blocking, but just 1 side. Maybe mounted wrongly or not sealed enough at the factory.

It happens things go wrong, that is what warranty is for when they leave the factory.

I do not believe the blocking of the pairing (when done properly) is causing it to melt.

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The valve reeds don't keep the cylinders insulated, why would they?

They are there to block the combusted gases to get back into the airbox.

As the exhaust is combined at the cat anyway, why insulate them?

Each cylinder has it's own outlet valves and they are closed on turn anyway.

Have you noticed this? There is no air-pump to let air flow from the airbox to the reeds.

Also the tubes are not made for high temps or pressure.

It's my opinion that the combusted air is pushed out by the cylinder, then reach the reed (that closes because of the pressure) it follows it path to the cat.

However, because of the combined pipes at the cat, the other pipe to cylinder no2 is getting under-pressure, so it sucks in air from the pairing and that waits there until the outlet-vavle opens to press combusted air out.

That mixture goes in the direction of the reed (that closes on it's turn) and follows it's way to the cat.

Then reed 1 opens and air is sucked into exhaust 1 etc...

I really believe your blocking (either plates or before) was leaking hot combustion air into the pairing-system or passing your reed somehow and made it melt.

Maybe the reed on 1 cylinder was never placed properly and melted because of passing gases.

So in my opinion the reed malfunctioned somehow even before the blocking, but just 1 side. Maybe mounted wrongly or not sealed enough at the factory.

It happens things go wrong, that is what warranty is for when they leave the factory.

I do not believe the blocking of the pairing (when done properly) is causing it to melt.

The cap sealing the valve cover port was in perfect condition and 100% air tight.

All the reed valves were installed correctly.

Did get out the volt meter and check those voltages from the PAIR connector like I asked? I'm really curious if you have PAIR activation with throttle off idie.

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You never answered my question about the exhaust.

Nor did you show any pictures of the melting.

I know the paring mod works and works good in combination with the flapper-mod.

I have done it on several bikes and all bikes improved handling and low RPM riding.

Why are you twisting and turning about the pairing being the problem of your melting?

Also you never explained why the reed should separate the cylinders.

I'm far more curious to know why you insist the pairing-mod should be the problem.

Answer those and I will start measuring for you tomorrow.

My VFR800Fi (2000) didn't melt, nor did my sons CBR1000RR (2006) and both run better then ever before.

So why did yours melt?

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You never answered my question about the exhaust.

Nor did you show any pictures of the melting.

I know the paring mod works and works good in combination with the flapper-mod.

I have done it on several bikes and all bikes improved handling and low RPM riding.

Why are you twisting and turning about the pairing being the problem of your melting?

Also you never explained why the reed should separate the cylinders.

I'm far more curious to know why you insist the pairing-mod should be the problem.

Answer those and I will start measuring for you tomorrow.

My VFR800Fi (2000) didn't melt, nor did my sons CBR1000RR (2006) and both run better then ever before.

So why did yours melt?

The plate with the melted seal was put back in because the parimeter seal was fine and that's what I needed for the block plate to work. I will remove it tomorrow and take a picture. In the mean time here is a picture of the reed valves. The set on the left were the leaking ones.

DSCN2491a

Though the exhaust back and forth won't enter the cylinder, as you stated, it could create turbulence in the exhaust flow, but more importantly, hot exhaust traveling back and forth thru the middle of the cylinder is something that needs to be avoided.
The PAIR only works at idle, and only when the bike is below normal operating temp. Blocking it makes has no effect since the control valve is closed under throttle. It's just a sugar pill. You think your grand idea made a difference, but it doesn't.
Sorry I didn't respond sooner but I thought you had taken the measurements and went away.
Don't bother measuring the circuit. I'll nook up a 12v led to the PAIR connector start the bike and shoot a video and show when the valve operates. Then maybe we can put this silly PAIR blocking thing to bed for good.
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Those look bad.

But I think I worded my question wrongly, are you using an after market exhaust-pipe or still the stock one?

As I'm using a DAM pipe and I was unable to ride at 3~4 rpm without hearing loads of pops and the bike had hickups at 50km/h or less.

With both modifications in place it simply runs far better, the hickups where so bad that my wife was banging me with her helmet at those speeds.

After making both mods, she's no longer banging me. I do not call that change a sugar pill.

However, the stock exhause pipe masks the pairing and flapper a great deal, people only notice it when fitting something else.

Mine:

image_1628.jpg

As for the LED, that is a great idea, I will connect one to my connector somewhere this week and have a spin with it.

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