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Discussion Starter #1
Hi all,

I've got some issues with the Aracer Setup and I can't figure out what's wrong. I have been at is for weeks :(
I've installed a 34mm takegawa intake, together with finishing up the aracer ECU install
I flashed the ECU with the 2018 170cc map (for EU abs grom) I put the fuel base at 75 as it was suggested on CJR tutorial
It start and idle at +/- 1600-1800 rpm but the AFR is at 10-11 , I have to put the fuel base lower around 60-65 to get to 13.1 (which shouldn't be I think, another neo kit I know from around here is at 85 on aracer and he has no problem)
Air screw is 3 turns out and Butterfly valve screw is at the 0 position (just barely touching the butterfly valve)
Valves clearance is correct.

If I give it some gas, sometimes it revs up normally, sometimes it bogs and won't go over 4k rpm, sometimes it get stuck there for 2 sec then revs up normally
and Another time it revs up but very slowly.
Sometimes it also get stuck for 1 sec at 3k rpm when going down as

Where could the issue lie?
Bad stock air screw? (It doesn't seems to do much when I turn it, it barely changes the AFR or RPM, until I remove it completely & then it goes to 3k rpm en 18 afr) a brass screw also needed for takegawa intake?
Butterfly screw wrongly positioned? Should it open the valve a little
Faulty aracer unit or 0² sensor?
I really don't know anymore.. any help will be greatly appreciated :)
 

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2020 Honda Grom
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I have a Koso throttle body with the brass screw, when mine started hanging up about 3k rpms I had to tighten the idle screw inward. Went from 2 turns out to just a little over 1 turn out I think.
 

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What size injector do you have?
 

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Discussion Starter #4
I have the Hi-flow Injector provided with the Neo kit. It doesn't say a specific size on the kitaco install papers
 

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Discussion Starter #5
I have a Koso throttle body with the brass screw, when mine started hanging up about 3k rpms I had to tighten the idle screw inward. Went from 2 turns out to just a little over 1 turn out I think.
Tried that with the stock air screw, engine still hesitating between working normally once and then bogging at 4k the second and lagging when going back down.
AFR around 11 when base fuel is at 75. Can it be that injector is broken and gives out more/less than before ? Or should I check valve clearance again?

It all worked once with base fuel at 84, the very first time. It was idling and reving correctly. Then it didn't anymore the day after :/ I did'n't do anything in between except putting the chimera back on and checking my valves just before starting it up again after 24h.
It seems engine isn't getting enough air when idling but the air screw doesn't give me more air. I tried to open the butterfly screw just a little bit . RPM goes up but afr stays low (10-11)
 

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2020 Honda Grom
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I don't know if it will work or not, but if I was in your shoes I would reinstall the base map (quick burn). And then adjust base fueling to around 13.1 regardless of where I thought it should be. Then adjust the idle and see how it performed. The wideband will help you keep an eye on afr so you can keep it safe. I heard someone mention that they used the stock non bbk tune for everything, even bbk bikes. They just let the autotune do it's thing.
 

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Discussion Starter #7
I reburned a lot already ^^ I took the 2018 BBK map as they said that the only map for abs EU grom on tutorials.
You mean reburn and leave base fuel at 100 and adjust from there?
 

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You can start at 75, but if it needs 65 to hit 13.1 then lower it. Might have to adjust it again if you mess with the idle screw.
 

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You said you re-used the stock air screw? You need the brass screw specifically for the Koso TB.

Until you run the brass screw, its a crapshoot.

The other thing that happened to me was valve clearances changing in first 100 miles. Made starting impossible.
 

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You said you re-used the stock air screw? You need the brass screw specifically for the Koso TB.

Until you run the brass screw, its a crapshoot.

The other thing that happened to me was valve clearances changing in first 100 miles. Made starting impossible.
Do you still need the Koso brass screw with the Takegawa intake? I wasn't sure if that one was machined differently.
 

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Discussion Starter #11
I thought that might be it but it is hard to find a brass screw in Europe. Takegawa doesn't make those anymore :(. Motorkit is copying one but it is taking a while.
Is the air screw also responsible for the weird Rev ups?
 

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Discussion Starter #13
I tested it some more today
I putted the air screw at 1.5 turns out and cleaned the sparkplug that was black
I checked the valves again.
I turned the bike on with a fresh 2018 bbk reburn and started at 75 fuel base.
It was idling correctly at 1500-1600 rpm but afr was 10 ish. I had to put the fuel base 51 at first to get afr around 12.9-13.3 and put gradually more fuel to 55-56 as the bike got warmer to stay in the 13 range
It was reving up normally but was getting stuck around 2500-3k rpm when going back down
Aracer app gives me 0.4% throttle still open but butterfly valve seems closed
I did a new TP learn and it had the same problem with the 0.4% when letting go. Butterfly screw isn't touching the butterfly valve & handle wires aren't too tight

I don't know if the issue is with any sensor or the Aracer ECU/AF1 or the airscrew or something else ><
 

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Try to turn the screw in just a little more, shoot for a 1400 rpm idle. That should stop the revs from hanging up. At least it did on my bike.
 

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Any luck with this?
 

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Discussion Starter #16
Didn't try further yet. Work got a little hectic ^^ I'll update when I go do some more testing.
 
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