[shush319]

Bought these for my 2017 (still waiting for the AF2), figured I would start a thread to document my experiences, as aRacer is new to me.

Back story on my Grom as it sits:

• Yuminashi 143 kit (cheap AF, don't judge me..... LOL), may go bigger in the future (164 kit is pretty cheap too )
• Old very rare in the USA, Yuminashi Hi Lift cam, originally came with their "160cc Ultimate" kit but was later sold separately (see specs below)
• Matching special Yuminashi Hi Lift (stock size) valves, double valve springs, and retainers (zero float even above 12.5k (limiter is set to 12.5 now & I try to stay off it))
• GromFatherz Rev Wedge, matched to a backcut OEM throttle body & ported head
• ported head, matched to a Finbro High Mount Exhaust (also rare in the USA)
• 120cc Yuminashi injector (have a 140 on standby, but do not see the need)
• Original DB Short Ram intake with K&N filter
• Yuminashi v9.1 Stand Alone ECU with BT app for tuning (old & hasn't been updated since 2019)
• WB O2 standalone gauge that also inputs to the Yuminashi ECU (BIG reason of all of this, no Autotune capabilities)

Because the Yumi ECU was for OG I had to repin the harness (will reverse before installing aRacer stuff), and cold start DID NOT WORK, actually had to unplug the CS connector cause it made a hideous constant clicking sound with this ECU. Even the cold start settings for the ECU app/PC program DO NOTHING, so I have to hold the throttle until it gets some temp into it or it will stall.

Bike runs really good once warmed up, tops out around 82 mph GPS with a 14t front & stock rear sprocket (full tuck) & is super fun to ride. But the amount of time I spend getting it tuned could have been better spent enjoying the ride, & its still needs more dialing in to be "right".

For reference, my girl's OG has the same 143 kit, TB cam, stock airbox with a Koso tube & BMC race filter, that was tuned & flashed on DHM's dyno. Hers is 14.2hp & a tick under 10ft lb torque, & never needs to be adjusted, just works every time. She always gets a jump on me off the line til about 40mph, then I roll right on by & leave her....

Will update this thread once I get the AF2 & MiniX installed. If anyone has any pointers to get me going in the right direction with the aRacer stuff, feel free to chime in. I have been studying for a while before pulling the trigger & kind of get the gist of it, but expect a bit of a learning curve.

Don't know if anyone remembers this cam or not, but here's what they had to say about it:

 

[shush319]

Great !!!
Lets see some fotos , when you can , cheers .

Only pic I can find right now: (edit: found another pic, both before I put an adjustable YSS shock, Core Moto brake lines & Seat Concepts flat seat on it.)

 

[shush319]

Both units have arrived, and are installed. Super simple stuff, and it allowed me to get rid of my stand alone WB O2 gauge.

Took a min to figure out how to do the initial Quick Burn, found no mention anywhere that I needed to set the access point in the X-Tune app for the ECU to connect to my home WI-FI in order to download the base map files needed, even CJR does not mention this on his site's instructions. Maybe there's another way, I don't know, but I managed to get it done.

Was also a pain to get the thing to start at first, but remembered I had the cold start solenoid unplugged due to my other ECU. Then getting it to idle, then idle w/o hanging at 3k after a throttle blip, but she's purring now.

Let the auto-tuning begin.... Too bad there is not a database to download map files closer to my mods to start with, but it is what it is...

List of upgrades/features already available (missed the rest below this). Really don't find the need for any that are not preinstalled until after I get it dialed in some, may add a quickshifter later.

 

[shush319]

Thanks for sharing this. Currently running the mini 5 with the AF1. Wonder if the X with af2 is worth upgrading to.

When cold, the aracer has never given me a solid idle. Once warm, it is fine.

I use auto tune but played around with the targer afr setting compared to stock aracer targets. I run it a bit more rich at high power settings.

One day I should get it to a dyno and have a tuner dial it in.

Mine seems to start right up & idle with no throttle input now..... Forgot how nice it was to have that, LOL.... The sub 2 minute Quick Burn is nice vs 10ish minutes on the old units.

Have you installed the AF2 sensor in the head like you had the old WB sensor or in the header pipe?

Sensor is in the head with an angled adapter.

 

[shush319]

Getting my feet wet on this. Can you put the WB O2 in the stock location?
I wasn't aware of the additional fees with the app. I need to plant more money trees.
Good to know about setting up the app on home wifi.

Yes, you can follow the instructions on CJR's site to get started, but when it came to the quick burn nothing worked until I found the extra setting to connect the MiniX to the home WIFI (sucks that aRacer has no documentation or instructions on their product yet). Was pulling out my hair for a minute & I cannot afford to spare any at my age, LOL.

You can get the WB sensor in the head where the stock sensor is, but you need this adapter & you have to cut the ridge off the head to be able to spin the adapter into the head. I had a straight adapter in there before but found this one that allows you to angle the sensor up better. Helps keep moisture out of the pricy sensor

 

[shush319]

That's awesome. Now I don't have to be limited on obtaining an exhaust with a hole and or having a fitting installed.

Same reason I went this route, did not want to trust my expensive (to me, definitely more expensive out there) & rare exhaust to some hack at an exhaust shop, & the guy I used to used to weld stuff for me died years ago.

Found a pic with the guard off when I installed it, you can see the fins I had to cut off with a die grinder (disregard the grinder dust).

 

[shush319]

Anyone have feedback on the accuracy of the aRacer temp readings? I also have a Koso Temp gauge & they are WAY off, unless I set the Koso to T-2A (Grom is supposed to be T-2), they they match up almost perfect. I also have to change the setting EVERY TIME I turn off the key now, very annoying.

 

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Bought the Yuminashi cam years ago when TB cam was new to the market & didn't have any real world reviews..... Held onto the TB cam in case the Yuminashi wasn't going to work for my bike, but fell in love with how high it in RPM it made power. Coming from a Two Stroke background, it just felt right to me, not much down low but when it started making power it came on strong & fast like a 2T. That was all on a stock bore, & the cam works even better on a 143...... Can't wait to see what it can do on a 164 .

TB (for OG & SF) is probably the best bang for the buck on the market given its price & proven performance.

Noticed you threw the S1 for 22 in that list, not many cams out there for those yet that I have heard of.

 

[shush319]

Anyone have feedback on the accuracy of the aRacer temp readings? I also have a Koso Temp gauge & they are WAY off, unless I set the Koso to T-2A (Grom is supposed to be T-2), they they match up almost perfect. I also have to change the setting EVERY TIME I turn off the key now, very annoying.

Think I answered my own question.... Pretty sure my TINY AZZ Battery Tender battery is on its way out or just not enough for the ECU. Ordered a nice 4ah gel battery to replace after reading about aRacer having connection issues with lithium battery's. May explain some of the AT issues I think its experiencing so far, will know Saturday. I'll just stick the BT battery in my scooter that only needs it for lights & the TrailTech dash.

This tiny thing is what I've had in there for a while now..... weighs around 1lb!

 

[shush319]

Thanks for sharing this. Currently running the mini 5 with the AF1. Wonder if the X with af2 is worth upgrading to.

When cold, the aracer has never given me a solid idle. Once warm, it is fine.

I use auto tune but played around with the targer afr setting compared to stock aracer targets. I run it a bit more rich at high power settings.

One day I should get it to a dyno and have a tuner dial it in.

Now that I've gotten some seat time & AT has been doing it's thing, cold starts are not as good as they were. Re-adjusted the idle set screw & idle air screw to try & get rid of the 3200 rpm hang, still does not run right unless 2.5 turns out no matter what I do so I have a Koso Idle Air screw on the way, hopefully that helps. Going to mess with "Temp Comp" fueling & see if I can get it better that way too....

 

[shush319]

Thing is just off.... Sometimes it reads & runs right (great when it does), other times I does not read the TPS until 1.8+%, which throws the tune off all over the map, will not idle, stalls at lights, PITA to start! Anyone else have this happen? Just bought, charged, and installed a NEW 4ah AGM battery with 80CCA, should be plenty since I have nothing else connected to the bike but a KOSO temp gauge that is on with the key..

 

[shush319]

I am sure your battery is fine.

I have the same complaints about idle. Sucks.

BUT it does the job where it counts near redline under demand.

I got used to having to milk the throttle a bit at idle to not stall . I avoid stopping in general

Run a higher than typical idle speed, adjusted by the cable adjustment and set screw, to get a reliable, but high speed (2K), idle.

Never paid attention to TPS after initial setup and autotune.

Noticed it because I was having to give 1/4+ throttle to keep it running & saw it was reading 0 for nearly all of that 1/4 throttle..... Was like, "no wonder it doesn't want to run right or idle". Reset TPS & still gave me fits. Pretty sure I have another TPS in a closet somewhere, will change it & reset in the ECU later, hopefully with better results.

Also wondering if low voltage at startup is affecting it also, may try putting the charger on it tomorrow AM & see if starting with a solid voltage has any effect either.

 

[shush319]

Just found a FB post talking about nearly the same exact issues as mine..... Apparently low voltage on the AF1/2 & ECU causes all kinds of issues. So bad someone even made a jumper harness to fix the problem!

Aracer AF1/AF2 Switched Power Adapter

100% Plug-N-Play power adapter for your Aracer AF1 or AF2 wideband module. Prevent your bikes battery from being drained by your AF module being wired to your battery. Also provides a constant 12v power source to prevent little hiccups in your AFR when tuning because of voltage drops if you are...

wickedgrom.myshopify.com

 

[shush319]

Great find. Had no idea.

Yeah, apparently the AF1/AF2 are powered by the ECU, which cause the ECU voltage to drop & make it freak out.

 

[shush319]

You can wire it (AF1) directly to the ignition (battery after turning the key) this is an installation option and runs great on mine. You can see the two options in the manual.

I have the AF2, no such wiring info or instructions came with it, lol.

 

[shush319]

AF2 is different & did not include the stand alone wiring, otherwise I would just tap into an accessory power wire & call it a day..

 

[shush319]

Did a little test & put the bike on a power supply @ 13.5V this morning to see if holding a steady voltage made a difference. Stalled 1st hit of the key, but when the ECU realized it was getting more power, 2nd attempt it fired up & idles without any struggle or throttle input. Battery voltage at the battery was 12.8V before I put the power supply on it, so I know the battery is putting out enough power. That harness, albeit kind of pricey @ $35 shipped (AF1 harness is cheaper), should work perfect for me. Seems the AF1-2 are drawing the power down on the ECU when plugged direct into it & causing odd issues for me, so separating the power supply of the two only makes sense.

Bike ran nearly perfect all the way to work (5 minute ride), ran closed loop until it was warm enough to auto tune, then switched it over to try & get a cleaner map the rest of the ride.

 

[shush319]

Another day another problem.....

Purchased Launch Control & it shows up as purchased in the app. The lock is gone on the xTune app monitor screen, but I cannot turn it on. Every time I click the LC "on" button the app crashes!

 

[shush319]

From my understanding you need to pin an extra wire ( from the green/white speed signal wire) to the ecu connector to have the launch control working.

I have already done this. Either way, the LC "ON" button should not crash the app.......

Recorded what happens when I click the ON button.... App just crashes & goes away.

New video by Sheldon Abbey

photos.app.goo.gl

This one shows how it acts when not connected to the ECU:

New video by Sheldon Abbey

photos.app.goo.gl

 

[shush319]

Report back after trying the fix!

Installed the AF2 power harness, now the idle voltage is a pretty steady 12v on the ECU (shown in the xTune app) rather than 11.3-11.4 at times even lower depending on if it wanted to idle normal or not.... battery is 13+ at idle & 14+ over 2-3k . Idles pretty good now, will have to get some seat time & see if AT can work out the bugs in the map. TPS seems to be reading better now too, had to loosen the screw & ever so slightly rotate it until it was reacting like it should & lock it down again.

Will give updates as it progresses or not. Also STILL trying to find answers why the xTune app crashes & closes every time I try to activate Launch Control, just updated the Wi-Fi via my PC which made the connection to my phone more stable, but did nothing for the LC issue....

EDIT:
Also noticed it showing 13v on the xTune app when riding, where before installing the WG harness it was low 12v when riding.