2020 yz250F Mapping Suggestions

kevinr
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kevinr
Edited Date/Time 3/25/2021 5:05am
Have a brand new (1.1 hour) 2020 yz250f with a twin air powerflow kit and full Yosh RS-4 exhaust. I had it out for the first time this weekend using the Keefer "free revving" map. On more than one occasion I got a backfire after high revving acceleration as soon as I shut off the throttle. I believe this is indicating a lean situation which I think I can just solve by bumping up all the "Fuel Injection" values by 1.
If I do this then what should I do with the Ingition values? Keep them the same? If anyone has a similar setup and has something that works I'd like to see what you have. I prefer the hard hitting map like the Keefer one so I don't want to lose that feeling but I don't want to be backfiring all the time entering corners.


Link to map: https://www.keeferinctesting.com/motocross-testing/2019/9/3/2020-yamaha…
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kevinr
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kevinr 3/22/2021 8:23am
3/22/2021 8:23am
I got a response from Kris Keefer and it led me to take a closer look at my maps and realized I didn't adjust the RPM and throttle positions from the base map. So if you're having this problem pay attention to the "position" so that you are not changing the fuel mapping at idle (aka 2K RPM). So this appears to be a case of user error.
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PTshox
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PTshox 3/22/2021 12:22pm
3/22/2021 12:22pm
Not following you on this... you can adjust Fuel injection or Ignition. Not sure what you mean..... I get the same popping....
Leeham
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Leeham 3/22/2021 1:39pm
3/22/2021 1:39pm
He means these values.
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kevinr
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kevinr 3/22/2021 4:52pm
3/22/2021 4:52pm
In the Yamaha tuner app they are “position” vs “value”

Only the stock (base) map has a RPM “position” of 2000. Most of the other maps leave it alone until 4500-5000. And most of them tune at much lower throttle positions.
Skerby
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Skerby 3/22/2021 5:43pm
3/22/2021 5:43pm Edited Date/Time 3/22/2021 5:45pm
Can you actually adjust the mapping at idle?

My buddy and I have a 20 and a 21, they both have fouled plugs. I understand that it is caused by idling, and I dont really need to idle the bike at all. But it sucks not being able to warm it up after a wash without ripping it up and down the driveway to make sure it cleans the plug.

Have keefer map installed now, it fouled out as I was trying to hook my phone up to change the mapping (had to bump the starter a couple times). hope this fixes it but Im still worried. It's not exactly easy to swap when the bike is dirty.

Not to mention not being able to warm the bike up sucks. So you have to like hit the track with a cold bike and try to take it easy until it warms up. Really, I have less than an hour on the bike, Im just pissed. Been racing 2 strokes my whole life and never fouled a plug, although I was careful to blow them out.
Skerby
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Skerby 3/22/2021 5:50pm
3/22/2021 5:50pm Edited Date/Time 3/22/2021 5:54pm
Seems like if I just went lower on the bottom left box of 'fuel injection' it would theoretically lean it out at idle, but I have read the app can't adjust the idle mixture.

If I can adjust it, do you think it would be a bad move? I would think you would want to just lean it out till it pops on decel. Do they make the bike crazy rich at idle to make it cool better?
kevinr
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kevinr 3/23/2021 4:46am
3/23/2021 4:46am
I haven't fouled any plugs yet although the bike only has 1.4 hours on it. I don't see why you should have to adjust the fuel with a TP (throttle position) of '0' (which would be idle I guess). All of the maps I have seen have at least '5' or above for TP.

I'm hoping to get the bike out tomorrow again if it doesn't rain with the correct Keefer map loaded and see if the popping goes away.
Skerby
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Skerby 3/23/2021 8:13am
3/23/2021 8:13am
Yea, I think I need to just ride it a little lol. Im sure fouling issue will improve, just sucks getting stuck out in the woods on brand new bikes all the time.
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Leeham
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Leeham 3/24/2021 12:53am
3/24/2021 12:53am
Make sure your idle is set high enough and let the bike sit there are warm up. If the idle is too low it will stall and foul a plug. Brothers 19 was set too low and would foul plugs on start up if I didnt have the throttle cracked just a bit for 20-30 seconds. Here is where mine idles at on the app.

Wiztardo
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Wiztardo 3/24/2021 6:11am
3/24/2021 6:11am
I have not had any plug fouling issues on my 2019 with that mapping when starting it to change oil or starting it up after a wash and letting it idle. Might be a dumb detail to consider; but I start it with the choke/ enrichener and let it idle for 30 seconds or so before disabling the choke. I haven't looked at the app, but it idles pretty high with that.

Also the bike is totally stock except for the Twin Air cage and that mapping.
Skerby
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Skerby 3/24/2021 8:21am
3/24/2021 8:21am
Wiztardo wrote:
I have not had any plug fouling issues on my 2019 with that mapping when starting it to change oil or starting it up after a...
I have not had any plug fouling issues on my 2019 with that mapping when starting it to change oil or starting it up after a wash and letting it idle. Might be a dumb detail to consider; but I start it with the choke/ enrichener and let it idle for 30 seconds or so before disabling the choke. I haven't looked at the app, but it idles pretty high with that.

Also the bike is totally stock except for the Twin Air cage and that mapping.
According to the manual, that choke actually leans it out. Seems like a typo but I should probably try this.

Survived a 2 hour trail ride last night, have to idle down a long hill at the end of the ride. Muffler hole looked like she was running real rich so still kinda worried. I'm just not going to let it idle at all for the time being. I'll run the piss out of this thing when I finally get it to a track. Might read the plug when I get home.
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kevinr
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kevinr 3/25/2021 5:05am
3/25/2021 5:05am
Rode with the updated maps yesterday at a smaller tight track. I started with the Keefer "Free Feeling" map but switched over to the Keefer "Aggressive 2" and I felt like it gave some extra pop out of tighter corners. I didn't notice any popping on deceleration at all.

Pic of Keefer Aggressive 2 map:

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