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Judging by the audio, the tune sounds dead-on and very healthy...at least at WOT. Just about everything else in this video strikes me as being light-years off, including all 3 gauges (A:F, speedo & tach). No way that's 80mph traffic. To put this bluntly, I don't believe that bike was anywhere near 157km/h actual speed. IMO, this video is archetypal...just enough info to capture the imagination without any substantial details.

Pushing the century mark requires ~30hp, possible with 180cc...at 3hp/cubic inch. That's close to the practical limit of specific output, for any normally-aspirated 4-stroke. Given the current "not ready for prime-time" status of their MSX125 parts, the vid is little more than an interesting curio at present.
 

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Judging by the audio, the tune sounds dead-on and very healthy...at least at WOT. Just about everything else in this video strikes me as being light-years off, including all 3 gauges (A:F, speedo & tach). No way that's 80mph traffic. To put this bluntly, I don't believe that bike was anywhere near 157km/h actual speed. IMO, this video is archetypal...just enough info to capture the imagination without any substantial details.

Pushing the century mark requires ~30hp, possible with 180cc...at 3hp/cubic inch. That's close to the practical limit of specific output, for any normally-aspirated 4-stroke. Given the current "not ready for prime-time" status of their MSX125 parts, the vid is little more than an interesting curio at present.

He has changed the gearing - reducing the gearing by around 15% on the standard so the speedo will be showing this 15% plus the normal 5% or so - so reading approx 20% faster than it is actually going - but that said 127 kph actual is still not bad !
 

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He has changed the gearing - reducing the gearing by around 15% on the standard so the speedo will be showing this 15% plus the normal 5% or so - so reading approx 20% faster than it is actually going - but that said 127 kph actual is still not bad !
Agreed, on both points. Still, the tach & A:F readings are beyond useless. If I were posting this, I'd want those two readings to be accurate - a way to clearly show that the setup is dialed-in and how it actually performs. I'd like to see them complete the development & testing and be able to offer proven, reliable, kits. I have dealt with Reggy in years past, he's always been a trip and that's okay. The parts were fine. That said, the way this program has been handled, to this point, I'm way too skeptical to invest in anything on their site...as in "that was then, this is now".

Not to hijack the thread but, when is someone going to address the speedo calibration issue? Having the speedo/odo up to 20% off isn't going to cut it for road use.
 

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Discussion Starter #9
Agreed, on both points. Still, the tach & A:F readings are beyond useless. If I were posting this, I'd want those two readings to be accurate - a way to clearly show that the setup is dialed-in and how it actually performs. I'd like to see them complete the development & testing and be able to offer proven, reliable, kits. I have dealt with Reggy in years past, he's always been a trip and that's okay. The parts were fine. That said, the way this program has been handled, to this point, I'm way too skeptical to invest in anything on their site...as in "that was then, this is now".

Not to hijack the thread but, when is someone going to address the speedo calibration issue? Having the speedo/odo up to 20% off isn't going to cut it for road use.
Maybe you should read the text under his video where he explains that the stock tach will only read to 9200 rpm and that the AF gage was not working properly and that this was just a preliminary test. I would not buy the kit based on this one video. I def would not buy it after reading the text as it is clear to me he is still in the testing stages.
 

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.....
Not to hijack the thread but, when is someone going to address the speedo calibration issue? Having the speedo/odo up to 20% off isn't going to cut it for road use.
In an automotive ECU, there is a way to change the speedo based on gear ratio and tire size (at least on GM ). Not sure if the stock or an aftermarket ECU will allow for that...
 

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Red flag parade

Maybe you should read the text under his video where he explains that the stock tach will only read to 9200 rpm and that the AF gauge was not working properly and that this was just a preliminary test. I would not buy the kit based on this one video. I def would not buy it after reading the text as it is clear to me he is still in the testing stages.
You're right, my bad for not clicking on the drop-down tab. Obviously, the A:F meter is inop; so why leave it in-place, powered and in-shot? This is supposed to impress viewers by showing the thoroughness of their testing? All it shows are two short banzai-blasts to an indicated 157km/h peak...which he claims is actual speed. Can't be actual, unless he's recalibrated the speedo and I saw no mention of that...consider the choices: omission, oversight, or lie.

Did you notice the way the engine was kept at high revs, not allowed to idle? What about the rest of the rev range & throttle positions? Getting peak power tuned is one thing, remapping the ecu (so that the motor will run reasonably efficiently & tractably in traffic, etc) is quite another. How about the rev characteristics? Sounds like a lightened rotating assembly...another detail omitted.
 

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In an automotive ECU, there is a way to change the speedo based on gear ratio and tire size (at least on GM ). Not sure if the stock or an aftermarket ECU will allow for that...
As luck would have it, I am familiar with the GM system. There's also the "speedo healer" for other bikes. Either would be fine here. Being able to make the changes to the factory ecu would be really slick...if that can be done. OEMs have been, shall we say, "less than eager" to allow access to their ecu maps.
 

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You're right, my bad for not clicking on the drop-down tab. Obviously, the A:F meter is inop; so why leave it in-place, powered and in-shot? This is supposed to impress viewers by showing the thoroughness of their testing? All it shows are two short banzai-blasts to an indicated 157km/h peak...which he claims is actual speed. Can't be actual, unless he's recalibrated the speedo and I saw no mention of that...consider the choices: omission, oversight, or lie.

Did you notice the way the engine was kept at high revs, not allowed to idle? What about the rest of the rev range & throttle positions? Getting peak power tuned is one thing, remapping the ecu (so that the motor will run reasonably efficiently & tractably in traffic, etc) is quite another. How about the rev characteristics? Sounds like a lightened rotating assembly...another detail omitted.
All good points. Like I said I would not purchase based on this one vid or the txt. Clearly at least to me it is a product in development. I hope he continues to post vids as he sorts everything out.

Sent from my DROIDX using HondaGrom.net mobile app
 

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I am so used to bikes reading 5 mph or so over actual speed, that I just add the 5 miles back to my highway speed, so it shouldn't be a problem with the Grom. In short order people will know if the speedo is off 4, 5, or 6 mph at 62 mph indicated with stock tires and sprockets anyway. I'll take my phone with gps on it the first day or so, then I'll know. I don't think he got 97 mph out of the Grom either. It's possible with a faired race bike of course. This is what 84 mph on a 125 looks like:
 

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Man you guys are a tough audience. I just go back to the first thing he wrote about the video.

"Some raw factory testing footage from the YUMINASHI 180cc kit for Honda MSX125/GROM.

Please notice that this footage was not recorded to deliver great images, neither to look good. This is raw footage and only mentioned for the Yuminashi R&D as a tool to work with...
Cylinder head on this video is the Yuminashi SX30 Head, with Yuminashi 31mm PGM-FI throttle body."

Seems like he is working on parts. Seems like he is testing and tuning parts. Seems like he is using video to help himself in that process.

Nice of him to share it with us IMO.
 

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It definitely revs a lot quicker than the stock engine. I sure hope the head and cam I ordered works out. They really shouldn't have taken pre-orders so early when it wasn't ready yet. I paid for my head and cam back in June, what i was not told is that it would not be shipping for a few months. I better be the first to get one.
 

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Man you guys are a tough audience. I just go back to the first thing he wrote about the video.

"Some raw factory testing footage from the YUMINASHI 180cc kit for Honda MSX125/GROM.

Please notice that this footage was not recorded to deliver great images, neither to look good. This is raw footage and only mentioned for the Yuminashi R&D as a tool to work with...
Cylinder head on this video is the Yuminashi SX30 Head, with Yuminashi 31mm PGM-FI throttle body."

Seems like he is working on parts. Seems like he is testing and tuning parts. Seems like he is using video to help himself in that process.

Nice of him to share it with us IMO.
People seem to be missing that part ;)
 
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