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Discussion Starter · #1 · (Edited)
MNNTHBX Intake – Why, Features, Installation, Outcomes, Photos

This posting describes the reasons for, the features, the installation, and the outcomes of installing an MNNTHBX intake with air filter and crankcase filter on my Z125, and includes some photos.


Summary


In summary, for those who hate to read a lot, the MNNTHBX intake has some really nice features, installs fairly easily, and seems to enable a bit more power per seat of the pants (not dyno) testing. But it adds a “sharpness” to the sound produced by the engine, and that sharpness is not pleasant to my ears, and becomes notably unpleasant at certain combinations of throttle, engine rpm, and road speed (see below for details). I'm not ready to make a final decision on this product.



Why I got the MNNTHBX intake

I had already “uncorked’ the exhaust by replacing the OEM exhaust with the Graves Z125 Full Titanium Carbon exhaust (see my “Graves Exhiaust” posting on the forum). That made a notable difference in power throughout the rpm range, even though the intake was still corked by the OEM airbox and intake, and even though I still don’t have an ECU tune that properly corrects for the new airflow capabilities.

Replacing the OEM airbox and intake with the MNNTHBX intake uncorks the intake, so that overall airflow is notably improved beyond what either just an exhaust or just an intake can do individually.

The exhaust and intake changes are both prerequisites that allow me to later obtain and load a better tune. That tune will be via installing a new tune file into the ECU via FTECU. Other Z125s owners who go down this same airflow and tune path might elect to use a Power Commander or Bazzaz unit instead to simply “modify” the signals that the ECU with OEM tune is sending to the fuel injection system, but I personally prefer an approach that does not modify the OEM wiring’s weatherproofing and vibration resistance.

In addition to the engine performance improvement, the MNNTHBX intake system, filter, and crankcase filter also saves 1.0 lb versus the OEM airbox and intake. A 1.0 lb weight reduction sounds small at first, until you realize that on a motorcycle that weighs just 212 lb before fuel, a combination of multiple small weight reductions like this can rather quickly get your Z125 below 200 lb, which adds even more agility to an already agile machine.


Features

The MNNTHBX intake has several notable favorable features:

- Non-metal intake tubing for less heating of intake air. This helps make more power. You may have noticed the cheesy reflective insulator sheet that Kawasaki placed between the throttle body and the engine cylinder and head. This is to try to reduce the excessive heat that the engine would otherwise transmit to the throttle body and the OEM intake tube and airbox). The MNNTHBX intake tubing is made of Silicone, which is VERY good at preventing heat transfer. In fact, I once successfully used silicone tubing for a small gas furnace exhaust pipe on an RV! Silicone can isolate even very high temperatures.

- The intake tube on the MNNTHBX is beautifully tapered down from the larger air filter opening to the smaller OEM throttle body opening. This too helps optimize airflow.

- The intake uses an Ideal length of intake tube between the air filter and throttle body for optimized engine performance

- A much more compact air filter setup eliminates the OEM airbox altogether, which makes the bike look much better (“airier”), and makes many maintenance and modification tasks easier (much better access for intake valve adjustment, better access to fuel injector)

The absence of the airbox also improves cooling airflow over the engine

Air filter maintenance is MUCH easier (servicing the OEM air filter requires removing the OEM airbox lid and even the horn as a pre-requisite to that!)



Negatives

Surprisingly, the MNNTHBX is heavier than its primary competitor, the Chimera intake. The Chimera with filter apparently weighs just 0.625 lb. The MNNTHBX intake with filter weighs 0.85 lb, but also requires a crankcase filter that adds 0.05 lb, so it really weighs 0.90 lb. I THINK this is because the Silicone tubing is very thick for better heat isolation. The Chimera, being thin metal, transmits heat very aggressively in comparison, and in that regard is actually inferior to even the OEM intake tube, which is plastic.

The MNNTHBX intake requires the separate crankcase filter because the silicone tube itself has no provisions for accepting the OEM crankcase vent hose. But, this too has a reason: feeding the crankcase vent into the intake tubing would disrupt intake airflow a bit and also introduce oily fumes into the throttle body and intake valve, so overall, the MNNTHBX approach of a separate crankcase filter is a justifiable design decision, despite adding another filter to check and replace from time to time.

The MNNTHBX intake alters the overall sound signsature of the Z125 notably under certain conditions, and some riders will like it or tolerate it and some riders won’t.



Installation

Remove seat by unlocking it from the bike

Remove side panels (each has 2 bolts behind fuel tank, 1 pushpin in front, and on my 2018 there is also 1 rear bolt by the rear footpeg. This rear bolt is NOT mentioned in either of the 2 videos I watched about the MNNTHBX intake installation process)

Remove horn

Unhook airbox drain line (front of airbox)

Unhook crankcase breather line (Rear left side of airbox)

Loosen hose clamp on bottom end of OEM intake tube (behind clutch cable)

Pull out “cable stay” on rightside of airbox

Remove airbox with intake tube (1 Philips on upper leftside, 1philips upper rightside, 1 under intake tube, pull downward and to right of the bike)

Install MNNTHBX intake tube, capturing 2 cables INSIDE the mounting piece before bolting it in. Use 1 of the 3 bolts that mounted the OEM airbox to fasten the intake tube to the same threaded hole that the airbox used. But don’t use the slightly longer one with the big “washer” head – that is needed for the cable guide that goes in the most forward airbox mounting hole on the right hand side of the bike. The mounting bracket goes FORWARD from the mounting bolt location, capturing the 2 cables (clutch and throttle) inside it, between it and the frame of the bike (see photo).

Tighten mounting bolt BEFORE tightening tube hose clamps! (so the tube mounting bracket is in a “natural” position and not stressed)

Tighten hose clamps at top and bottom of tube

Install air filter using hose clamp

Install crankcase filter onto crankcase hose, using the provided “circle clamp”

Secure crankcase filter to motorcycle frame using plastic zip tie (see photo)

Remount horn

Plug horn back in – polarity of its connections does not matter

Save the rubber bushings from the airbox, which secure the sidepanels, so if you later add the optional MNNTHBX Carbon Fiber support rod, you can snap the pins in the sidepanels into the bushings to make the panels more secure (but not nearly as secure as they were with the factory airbox to plug into)


The entire installation process took me about 1.5 hours, but that included taking the kit, tools, weigh scale, rearstand, and Z125 to the work area, and also the extra 10 minutes or so to remove the side panel bolts by the rear passenger pegs, which are not even mentioned in either of the 2 videos I watched, and which was made a bit more complicated and slower by the way the Graves exhaust is secured to that same bolt on one side. The “few minutes install” I have heard about might be possible for someone who does it FREQUENTLY, but an amateur, like me, should allow between an hour and 90 minutes to get the entire job done including putting away the tools and old parts afterwards.

But no technical skills are required, other than knowing not to overtorque bolts or screws, and how to ensure that cables are kept properly routed and untensioned.



Outcomes


I have put on 140 kilometers = 87 miles with the MNNTHBX intake on the bike.

I noticed immediately on startup of the engine that the MNNTHBX intake adds sound – but it is NOT the “wooshing” sound you might imagine moving more air might make, but rather a sound that changes in character with differing combinations of throttle, engine rpm, and road speed.

At idle, it is a rather satisfying “growl” that adds to the growl that the Graves exhaust introduced.

At low cruising throttle openings, it changes over to a much “sharper” sound that is not pleasing but not particularly annoying.

At larger engine loads and throttle openings, it becomes a pronounced 2-stroke-dirt-bike-like sound that is, at least to my ears, rather unpleasant and too loud.

It is definitely not the Graves exhaust doing this. I have had the graves exhaust on the bike for several rides already, and it has sounded great: very pleasing, lower frequency than the OEM exhaust (a “growl”), and not TOO loud, under any combination of load/throttle/speed. But as soon as I added the MNNTHBX intake, the overall sound signature of the bike changed a lot. I have NO idea why the MNNTHBX intake does this.

The new sound is so much less pleasing than the sound with the Graves exhaust alone that I am honestly not sure I will keep the MNNTHBX intake on the bike. The new sound detracts from the riding experience, at least for me, when climbing hills or needing to ride at higher speeds. But, I’m going to give it a bit more time and kilometers, doing more specific experimentation with load/throttle opening, road speed, gear selected, and ambient outside temperature, before I make a final decision.

I’ll say one thing though right now: If the MNNTHBX intake, which is made of noise insulating silicone, makes this much noise, then the Chimera intake, which is metal, must be even louder.

With BOTH the Graves exhaust and the MNNTHBX intake installed, there was, right after initial startup with the new combination, just a very faint and half-spirited weak backfire sometimes, not always, when closing the throttle for a gear shift. It was a VERY weak backfire, but it made me wonder if now, with both intake and exhaust uncorked, and no compensating richer tune yet installed, the engine air/fuel ratio is just a bit lean, even at moderate throttle settings (the weak backfiring was occurring in moderate, part throttle riding, not hard riding).

However, that weak backfiring on closed throttle for gear shifting disappeared after my first 24 km ride. This could be for one of at least two different reasons:

1. The outdoor temperature during the first 24 km was 15 degrees C = 59 degrees F. The riding between 24km and 140 km was in outdoor temperatures that ranged from 8 to 10 degrees C = 46 to 50 degrees F. This COULD make a difference.

2. The ECU may have adapted its fuel mapping to the new airflow over the course of miles run after the changes were made

I need more time to study this.

As for performance, it’s hard to judge without having access to a dyno, but it does feel to me that the bike can now climb hills without downshifting just a bit easier than it did with the OEM intake or with the OEM intake and only the Graves exhaust. Again, I’ll reserve judgment until I have more miles put on and under more combinations of load, throttle opening, road speed, road topography, and ambient temperatures.

Finally, as you can see in the photo below, the sparkplug after 140 kilometers looks healthy – a nice “coffee color” on the center electrode.


Summary

While I like the features and while the performance does seem improved, I’m not personally ready to make an overall judgment on the MNNTHBX intake, because its varying sound signature under differing conditions does not make me happy, at least at this point. I’m going to give it some more testing time before I make a final decision.



Photos

There are a few things to note in the photos:

- The MNNTHBX air filter sits much higher above pavement level than the OEM filter. It is also completely protected on each side by the side fairing panels.

- Note how the hose clamp screws for both the top of the intake tube and for the air filter clear the throttle and clutch cables if you position the hose clamps sensibly

- Detailed oriented folks looking at how it snugs up to the frame may wonder if the close proximity interferes with airflow. No, it’s actually got a LOT less interference than the OEM airbox with its puny approximately ¾’ size air entry hole!

- Note carefully the positioning of the OEM cable clip forward of and below the air filter. This is the correct orientation of that cable clip, even though it forces the throttle cable to an almost 90 degree bend. If you flip it upside down, trying to alleviate that almost-90-degree turn, the cables will interfere with, and abrade over time, the air filter.

- Note the long, gracefully tapered shape of the silicone intake tubing as it simultaneously curves down towards the throttle body. This would be harder to do in metal tubing without special tooling and presses.

- Be careful in positioning the clamp on the bottom end of the silicone tubing, so that you can reach it PROPERLY (not at a severe angle) with a Philips screwdriver to tighten it.

- Note how easy it is now to get to the intake valve adjuster, and to the fuel injector

- Note how “airy” the space around the top of the engine is now. Imagine the enhanced airflow now possible over the top of the engine at any speed

- Note how the (red) crankcase air filter is secured to the crankcase vent hose with a c-clip, and to the bike with a plastic tie, and how it sits HIGH above the pavement to stay cleaner.

- Note that while the air filter and crankcase filter are both nicely protected from road spray, rain at highway speed will still get at the 2 filters, and MNNTHBX offers an optional “pre-filter” (“sock”) that stops water entry into the main filter, for the main engine filter only. This should be viewed as a necessity to buy, as even if you NEVER ride in the rain, you do wash your bike regularly (I hope), and a spraying water hose WILL get water into that engine intake filter. The pre-filter is inexpensive.

- In the photo of the bike from the front, if you start at the TOP of the yellow trim decal on the sidepanel, and move slightly downward and towards the center of the photo, you can see the new air cleaner “peeking” through the louvers in the sidepanel, so yeah, it’ll get wet in driving rain on the highway, or even at city street speeds.

- Note the nice color and overall appearance of the sparkplug after the first 140 kilometers of riding with the intake installed.

I hope this thorough description of the MNNTHBX intake will help anyone considering getting one and wanting some feedback from a current user before doing so.

Jim G
 

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With BOTH the Graves exhaust and the MNNTHBX intake installed, there was, right after initial startup with the new combination, just a very faint and half-spirited weak backfire sometimes, not always, when closing the throttle for a gear shift. It was a VERY weak backfire, but it made me wonder if now, with both intake and exhaust uncorked, and no compensating richer tune yet installed, the engine air/fuel ratio is just a bit lean, even at moderate throttle settings (the weak backfiring was occurring in moderate, part throttle riding, not hard riding).

However, that weak backfiring on closed throttle for gear shifting disappeared after my first 24 km ride. This could be for one of at least two different reasons:

1. The outdoor temperature during the first 24 km was 15 degrees C = 59 degrees F. The riding between 24km and 140 km was in outdoor temperatures that ranged from 8 to 10 degrees C = 46 to 50 degrees F. This COULD make a difference.

2. The ECU may have adapted its fuel mapping to the new airflow over the course of miles run after the changes were made

I need more time to study this.


Jim G
.
After I installed my FMF exhaust I had CRAZY INSANE decel pop and like yours it stopped after 10-20 miles and hasn't decel pop once since . ECU learned is my guess
.
( I have no 02 sensor (and yet it still learned) and only a slightly opened up stock air box and a BMC air filter)
 

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Discussion Starter · #3 ·
By the way, today's gas top-up after 140 kilometers calculated out to just over 95 miles / US gallon, and that included some aggressive acceleration and highway riding as part of the testing.

Jim G
 

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This is going to sound crazy, and it probably is, but I wonder if the intake noise with the Mtake could be reduced with something as simple as a zip tie. Doesn't the flow of air have to pulse through the intake tube? In other words when the intake valve opens there is a sudden flow of air and when the valve closes the airflow suddenly stops. Is it possible that the air pulses going through the flexible silicone tube, cause it to vibrate, and effectively turn it into a circular version of the cone of an audio speaker?
I don't know if this is actually happening, but IF it is, tightening a large zip tie around the middle of the intake tube might dampen the vibration and reduce the noise volume. Of course the wire tie would have to be tight enough to dampen the vibration, but not so tight that it distorts the tube.
I don't have an Mtake, so I can't try this myself, but for those of you who do: If you are bored, feel like trying an experiment, and have a wire tie laying around; you may want to try this and see if it makes any difference.
OK, my flash of insanity has passed, please feel free to return to your scheduled activities :)
 

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Discussion Starter · #5 · (Edited)
This is going to sound crazy, and it probably is, but I wonder if the intake noise with the Mtake could be reduced with something as simple as a zip tie. Doesn't the flow of air have to pulse through the intake tube? In other words when the intake valve opens there is a sudden flow of air and when the valve closes the airflow suddenly stops. Is it possible that the air pulses going through the flexible silicone tube, cause it to vibrate, and effectively turn it into a circular version of the cone of an audio speaker?
I don't know if this is actually happening, but IF it is, tightening a large zip tie around the middle of the intake tube might dampen the vibration and reduce the noise volume. Of course the wire tie would have to be tight enough to dampen the vibration, but not so tight that it distorts the tube.
I don't have an Mtake, so I can't try this myself, but for those of you who do: If you are bored, feel like trying an experiment, and have a wire tie laying around; you may want to try this and see if it makes any difference.
OK, my flash of insanity has passed, please feel free to return to your scheduled activities :)
You may be onto something, Spaceteach. A zip tie just might be enough to make a difference! I have been thinking about other possibilities too. For example:

- Wrapping the silicone tube with a sound deadening foam tied in place via zip ties. This does not create any "aesthetic" issues since the entire intake and filter assembly is hidden behind the side body panels.

- Zip-tieing the silicone intake tube to something rigid on the bike frame, to dampen any vibration in the tube

However, the big issue is likely to be that any sound created in that silicone intake, or within the throttle body (whatEVER the source of the sound is), is still going to come out through the air filter, which of course we do not want to obstruct in any way since our entire goal here was to remove intake airflow restrictions.

But zip tying the silicone tube, and even maybe the air filter, to something rigid is worth trying. The noise created by that intake tract is pretty unpleasant. This is probably why Kawasaki made that huge plastic airbox, and why they made the air entry hole INTO the airbox so tiny!

Even mounting a slightly larger air filter, or a cone shaped versus cylindrical air filter COULD maybe help, as changing the size and/or shape of the "chamber' inside the air filter will make a difference to the sound, if there is sufficient room (I'll have to check to see how much more room could be grabbed, if any).

This sharp intake noise level is ironic in that this engine is both TINY in displacement and also rather mildly tuned by motorcycle engine standards (Even though the rev limit is 9800 rpm, it actually makes its peak power in the 7000 to 8000 rpm range, and peak torque in the 5500 to 6000 rpm range!).

Jim G
 

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I'm just guessing here, but I think the noise is a result of a rapidly closing intake valve shutting off a high velocity air stream. Have you ever had a water faucet with levers that only rotated a quarter turn? On mine if I have water flowing and turn it off as fast as possible, I'll hear a "thud". If the water is flowing full force, the thud is pretty easy to hear. If I only have the faucet half open and slam it closed I can barely hear it. Air has a lot less mass than water (and it's compressible) but I suspect the same type of thing is happening with the intake. The less restrictive (higher flow) the intake, the louder the sound. I also think the tube is acting as a sounding board. Think unplugged electric guitar (pretty quiet) vs a hollow body acoustic (pretty loud).
I wonder what it would sound like if a sock type foam intake filter was attached directly to the throttle body.

Ah well, I'm probably way out in left field and completely wrong about all of this, but that's my story and I'm sticking to it.
 

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Discussion Starter · #7 · (Edited)
. . .

I wonder what it would sound like if a sock type foam intake filter was attached directly to the throttle body.
. . .
I like the simplicity of the foam filter right on the throttle body, but I can think of 4 issues:

- There may not be enough physical room behind the throttle body for any decent sized filter (see the photo in this thread)

- Foam filters don't pass air as well as the corrugated cotton filters do. Foam filters are preferred by some offroad riders primarily because they let less of the really tiny dust particle through, are easier to wash mud off of, and are easy to "recharge" with air filter oil "in the field" when necessary, but they aren't the best for airflow (i.e. they are well suited for the dirt environment but not necessarily very "high performance" overall).

- You would lose the "tuned intake" effect which the engine builders tell us is so important

- The intake air would be hotter, since the air would be sucked from right behind the throttle body,which is SO close to the hot cylinder head compared to the MNNTHBX air filter which is well above and actually almost forward of the cylinder head (see the photo).

BUT, I wonder if a foam sock like you suggest might STILL be better than the convoluted air path and tiny airbox opening of the OEM setup.

One nice thing about an engine so small and low powered is that even in the absence of a dyno anywhere close by, once the engine is through the break-in period, I can do a full throttle top speed test on the local high speed highway (posted at 120 KPH = 74.4 MPH) and STILL be well under the speed limit! :) I could go past any speed trap with impunity!

So, I could compare the top speed with the MNNTHBX intake to the top speed with the foam sock filter, which would tell us if there actually is a big difference or not.

I wonder if there is a foam sock filter with a 24mm mounting diameter and if there is enough flange on that throttle body to properly hose clamp it in place (As I recall from my brief humorous foray into dirt biking, foam filters don't have a real "flange" to set a hose clamp onto), and enough space
for the filter to "fit" . . .

Jim G
 

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Discussion Starter · #8 · (Edited)
A foam filter would muffle sound much better than a cotton filter. I wonder if a foam filter mounted onto the upper end of the Mtake, instead of the corrugated cotton filter, would work at all well. That approach would preserve the tuned length of the silicone intake tube, but still muffle the sound at least a bit. I wonder how much more restrictive the foam filter would be versus the corrugated cotton filter.

The cotton filter would for sure need a pre-filter to keep rain from soaking it. I suspect wet foam wouldn't pass much air.

Jim G
 

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One nice thing about an engine so small and low powered is that even in the absence of a dyno anywhere close by, once the engine is through the break-in period, I can do a full throttle top speed test on the local high speed highway (posted at 120 KPH = 74.4 MPH) and STILL be well under the speed limit! :) I could go past any speed trap with impunity!

So, I could compare the top speed with the MNNTHBX intake to the top speed with the foam sock filter, which would tell us if there actually is a big difference or not.

Top speed is not the be all and end all. It will be determined by the gearing, with me on it (105kg) and just a pipe mine would only pull top gear redline on a slight downhill, now with all my mods it will do it on a slight incline, no difference in "top speed" but a massive difference in "performance", if you know what I mean:grin2:
 

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BTW, I was shocked as the how loud the intake noise was when I did mine, I am used to it now and don't even notice it.
 

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Discussion Starter · #11 ·
BTW, I was shocked as the how loud the intake noise was when I did mine, I am used to it now and don't even notice it.
Phil which exhaust are you running?

What mods beyond intake and exhaust?

Did you do the exhaust first and then intake, or vice versa?

Jim G
 

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Discussion Starter · #12 ·
At what rpm does the rev limiter kick in? Is it at the redline of 9800 or, like most motorcycles, somewhere a bit higher?

Jim G
 

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A foam filter would muffle sound much better than a cotton filter. I wonder if a foam filter mounted onto the upper end of the Mtake, instead of the corrugated cotton filter, would work at all well. That approach would preserve the tuned length of the silicone intake tube, but still muffle the sound at least a bit. I wonder how much more restrictive the foam filter would be versus the corrugated cotton filter.

The cotton filter would for sure need a pre-filter to keep rain from soaking it. I suspect wet foam wouldn't pass much air.

Jim G
Fox Fader tried one on the oem air tube. Checkout post 18 in the $21.50 DIY Intake thread.
 

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Phil which exhaust are you running?

What mods beyond intake and exhaust?

Did you do the exhaust first and then intake, or vice versa?

Jim G

Pro Circuit exhaust, Bazzaz and 143 power up kit (head, cam, intake etc) Got the exhaust put on before I picked the bike up, did 2k on it and then did the BBK, Mtake and Bazzaz at the same time.
 

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At what rpm does the rev limiter kick in? Is it at the redline of 9800 or, like most motorcycles, somewhere a bit higher?

Jim G

With the stock ECU it is right at the start of the redline, 107kph with OE gearing
 

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I am fairly certain the intake noise is not from the rubber "hose" between throttle body and air filter. Why do I make this proposal? Because on my KAYO, there is nothing that can vibrate and the intake noise is very loud. The intake is an aluminum manifold, carb, and filter clamped on the carb. The intake noise is fairly loud on this but is offset by the loud racing exhaust. If it had a mild muffler on it, the intake would then be the overwhelming noise and seem overly loud.

There might be a small amount of noise from the rubber tube, but I don't think that's where the majority is coming from. If someone can prove this wrong, then small gains could be made by replacing that with a rigid aluminum tube between the filter and throttle body.

New carb part 1 New carburetor and manifold/mount.
part2 Update - New carb. number 2
part3 New carb. - part 3
 

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Discussion Starter · #18 ·
With the stock ECU it is right at the start of the redline, 107kph with OE gearing
With OEM gearing and OEM tires, 60 mph = 8623 rpm.

With OEM gearing, 107kph = 66mph = 66/60 x 8623 rpm = 9540 rpm, not 9800. So, if you are seeing 9800 rpm INDICATED on the tachometer when the rev limiter activates, 67 mph on the speedometer can't be right.

Both he speedometer and tachometer are proven liars.

I know that on my own Z125, the speedometer reads 7% high, and the tachometer reads over 10% high in STEADY STATE SPEED, and despite that, I have accidently hit the rev limiter in lower gears, EVEN THOUGH THE TACHOMETER READ IN THE LOW 9000s at the time! That means, not only does the tach read high in "steady state" measurements, it instead LAGS severely under quick acceleration!

So, don't believe what either of the 2 instruments is telling you.

Trying to do any testing that depends upon reasonable tachometer and speedometer accuracy OR lack of lag in either of them, is pretty much futile.

I think maybe Kawasaki bought those instruments from the same manufacturer that they bought the "sealed" chain from. :)

I think the Z125's low price point (notably lower than the Grom's) is manifesting here, bigtime. The instruments are like some women: very pretty to look at, but contradictory, and impossible to logically understand. :)

Jim G
 

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Discussion Starter · #19 ·
I am fairly certain the intake noise is not from the rubber "hose" between throttle body and air filter. Why do I make this proposal? Because on my KAYO, there is nothing that can vibrate and the intake noise is very loud. The intake is an aluminum manifold, carb, and filter clamped on the carb. The intake noise is fairly loud on this but is offset by the loud racing exhaust. If it had a mild muffler on it, the intake would then be the overwhelming noise and seem overly loud.

There might be a small amount of noise from the rubber tube, but I don't think that's where the majority is coming from. If someone can prove this wrong, then small gains could be made by replacing that with a rigid aluminum tube between the filter and throttle body.

New carb part 1 New carburetor and manifold/mount.
part2 Update - New carb. number 2
part3 New carb. - part 3
I see that you are an avid and determined experimenter! And I think you could be right that the sharp loud noise is not something that I with my meager knowledge and resources will be able to eliminate.

I may need to make a decision as to what I want more - sound level and character that I like OR more performance than I can get with the OEM intake. I can't seem to have both.

I have a couple more things to try, centered mainly on using more revs and less throttle when accelerating (i.e. stay in lower gears longer), and some experimentation on what effect ambient temperature has on this noise issue. If I'm forced to make a choice, I am leaning towards returning to the OEM intake, as the Mtake noise is a bit "too" annoying to me personally. It prevents "peaceful", relaxed riding of country roads at times when that is all I want. Someone with a stronger focus on performance will likely disagree with me.

Jim G
 

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Discussion Starter · #20 ·
. . .

There might be a small amount of noise from the rubber tube, but I don't think that's where the majority is coming from. If someone can prove this wrong, then small gains could be made by replacing that with a rigid aluminum tube between the filter and throttle body.
. . .
That product exists - the Chimera intake - the competitor to the Mtake. But it too makes a lot of noise, as reported online by multiple users. So, we don't appear to see any solutions.

Jim G
 
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