2021 CRF 450 starting problems

Jeremy_Watson
Edited Date/Time 3/17/2021 9:50pm
I just picked up a new Honda 450R, put about 15 minutes on it. Changed map settings and removed back fire screen. Restarted it and blipped the throttle and I guess fouled a plug. Battery went dead shortly. I heard map #1 fouls plugs. Will it help removing the back fire screen for performance or will the ECU automatically add more fuel because of the added air? I have to buy a new plug on Tuesday and try again. I bought a lithium battery charger and battery is full currently. Any feed back?
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Meister
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Meister 1/18/2021 4:14pm
1/18/2021 4:14pm
Plug probably fouled. Put a 9 in it. If it continues, contact TDR motorsports, or tokyo, twisted, or xpr for a tune.

Rumor has it, honda will be releasing a new flash at dealer level very soon.
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Cademx14
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Cademx14 1/18/2021 4:18pm
1/18/2021 4:18pm
We have not removed the backfire screen, however the bike has been rode in all three maps, over 15 hours, no issues?? In map 1 the bike does backfire on startup almost every time, and the mapping issue is most notable in map 3?? We added the Ti Yosimura RS12 exhaust which definitely increased power especially in the mid to top but it also made the map 3 a touch more finicky down low. Map 1 now feels as strong as map 3 did with stock exhaust. Yours is the second one I have heard of fouling a plug, and I know one had been remapped. I will say they are fast, real fast for a stock 450, I’m just giving the tuners some time to sort out the mapping before getting it done. Not sure if that helps but that been our experience
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Crisb133
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Crisb133 1/23/2021 1:21pm
1/23/2021 1:21pm
well i also have a 2021 crf450r and after about 2 hours of ride time. i went to the track today unloaded the bike went to cold start it, hit the button it coughed once and that was it. all it will do know is just crank and crank and crank. in my opinion it has fouled a plug, this thing seems to run rich as hell. and i agree with all about the mapping issue however i feel the biggest problem is in the the air to fuel mixture. picked up a new plug and will install it as soon a qualifying is over and will post a photo of my plug, and let yall know if it indeed was the plug.
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Bruce372
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Bruce372 1/23/2021 2:16pm
1/23/2021 2:16pm
Maybe you can rejuvenate the old plug by heating with the flame from a ciggie lighter?
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KMC440
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KMC440 1/23/2021 2:21pm
1/23/2021 2:21pm
Used rejuvenate mine with brake cleaner and a wire brush. Especially if I just drove to a track, paid to ride and didn't have a spare.
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Crisb133
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Crisb133 1/23/2021 6:09pm
1/23/2021 6:09pm
Update it was a plug issue . Put in new plug . I went with a 9 instead of the 10 . i


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beamer
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beamer 1/23/2021 6:22pm
1/23/2021 6:22pm
Very rich for sure
captmoto
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captmoto 1/23/2021 7:14pm
1/23/2021 7:14pm
That's dirty, like oily dirty.
Tokyo_Tiddler
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Tokyo_Tiddler 1/23/2021 9:57pm
1/23/2021 9:57pm
So much for the benefits of fuel injection! They should be set up for a perfect mix at least for start up and idle. To date, carbs perfectly set up make more peak power than fuel injection which has been know for quite a well. Fuel injection has its benefits but what is the point of they cant provide a program that allows for the benefits. Heck.. being able to pick up a screwdriver and a few tiny jets to fix it now sounds like that now would be a technology leap forward if Honda can't even provide a program to keep it from running pig rich at start up.
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Jeremy_Watson 1/24/2021 1:29pm
1/24/2021 1:29pm
I installed a #9 plug, map 2 and been doing fine. Playing around the house and MX track. I may take out the back fire screen....
yak651
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yak651 1/24/2021 1:40pm
1/24/2021 1:40pm
A motocross bike fouling plugs, what is this 1990 again??
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Bruce372
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Bruce372 1/24/2021 1:57pm
1/24/2021 1:57pm
yak651 wrote:
A motocross bike fouling plugs, what is this 1990 again??
Didn't you hear, every carbed bike since 1990 ran perfectly
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MotofactioN
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MotofactioN 1/24/2021 2:24pm
1/24/2021 2:24pm
shouldve gotten an rmz450. 55 hours and zero issues. Cool
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Wolfey
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Wolfey 1/24/2021 2:47pm
1/24/2021 2:47pm
Crisb133 wrote:
Update it was a plug issue . Put in new plug . I went with a 9 instead of the 10 . i[img]https://p.vitalmx.com/photos/forums/2021/01/23/474535/s1200_PXL_20210123_214323770.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2021/01/23/474536/s1200_PXL_20210123_214326935.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2021/01/23/474534/s1200_PXL_20210123_214331406.jpg[/img]
Update it was a plug issue . Put in new plug . I went with a 9 instead of the 10 . i


Did yours come with a 10 in it? Mine came with a 9. It’s a SILMAR9A9S.
LT423
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LT423 1/24/2021 5:23pm
1/24/2021 5:23pm
This Thursday I got my first ride on my 450WE. We are in winter here. Bike was at 25 degrees in back of truck. Went to Cedar Lake indoor in Wisconsin. Bike started fine, I got my first 4 laps on it. Notice it ran rich on bottom. I was in map 2. Parked it for 10 minutes for next open practice. Bike would not start. I was pretty pissed. I took it apart to pull plug. I had SILMAR10A9S in it OEM. I cleaned it with quick start fluid and emery cloth. Got it to start, rode the entire night. Note that this indoor track is 2nd gear low to mid RPM. It certainly runs rich on bottom. I definitely feel the issue. I called dealer to see if they hear of a factory ECU warranty recall. They said not yet. I did like how well the new chassis turns, so it has potential. Too bad I have to spend more money on this to get the bike complete.
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Meister
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Meister 1/24/2021 6:50pm
1/24/2021 6:50pm
Lt, I dont know if you've seen any of my posts, but TDR motorsports here in Ohio spent some time with my WE on the dyno and came up with a much cleaner map for both 2 and 3.. just cleaning it up gained 2hp too.. bike was very rich down low and very lean mid-top..
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Chris99Flannery 1/24/2021 11:55pm
1/24/2021 11:55pm Edited Date/Time 1/24/2021 11:55pm
Sheeet... my cr125 doesnt even foul plugs!
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SKIDLID
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SKIDLID 1/25/2021 2:25am
1/25/2021 2:25am Edited Date/Time 1/25/2021 2:41am
LT423 wrote:
This Thursday I got my first ride on my 450WE. We are in winter here. Bike was at 25 degrees in back of truck. Went to...
This Thursday I got my first ride on my 450WE. We are in winter here. Bike was at 25 degrees in back of truck. Went to Cedar Lake indoor in Wisconsin. Bike started fine, I got my first 4 laps on it. Notice it ran rich on bottom. I was in map 2. Parked it for 10 minutes for next open practice. Bike would not start. I was pretty pissed. I took it apart to pull plug. I had SILMAR10A9S in it OEM. I cleaned it with quick start fluid and emery cloth. Got it to start, rode the entire night. Note that this indoor track is 2nd gear low to mid RPM. It certainly runs rich on bottom. I definitely feel the issue. I called dealer to see if they hear of a factory ECU warranty recall. They said not yet. I did like how well the new chassis turns, so it has potential. Too bad I have to spend more money on this to get the bike complete.
On a side note LT nice to see you here, and on a new Honda. I talked to JH last week and he said you got a new bike.

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spimx
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spimx 1/25/2021 6:41am
1/25/2021 6:41am
yak651 wrote:
A motocross bike fouling plugs, what is this 1990 again??
Bruce372 wrote:
Didn't you hear, every carbed bike since 1990 ran perfectly
The last generation of carbureted 450s were great bikes.
2
RCMXracing
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RCMXracing 1/25/2021 8:26am
1/25/2021 8:26am
Following... as soon as anyone hears about a recall please post.
If you wanna cut your troubles on the rich mapping 50/50 T4/pump really helps. Been riding in 50-60 deg and although it feels a little fat at low throttle, it’s honestly not that bad. Think the T4 is why.
H4L
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H4L 1/25/2021 5:06pm
1/25/2021 5:06pm
Meister wrote:
Lt, I dont know if you've seen any of my posts, but TDR motorsports here in Ohio spent some time with my WE on the dyno...
Lt, I dont know if you've seen any of my posts, but TDR motorsports here in Ohio spent some time with my WE on the dyno and came up with a much cleaner map for both 2 and 3.. just cleaning it up gained 2hp too.. bike was very rich down low and very lean mid-top..
If you don’t mind me asking what was the peak HP # (after the tune) & what kind of dyno was it run on ?
Meister
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Meister 1/25/2021 5:18pm
1/25/2021 5:18pm
Varies by dyno from what I understand but on his dyno (the make, I am unaware of) stock was 55.76 and with clean up we were at 58.25. We went in to it not searching for absolute peak HP but rather clean up the mess honda left.
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Jeremy_Watson 1/26/2021 12:11am
1/26/2021 12:11am
Now I read that Honda has defective Injector Assembly and will replace them to correct the plug foul problem. Interesting...
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313 SlowDown 1/26/2021 2:42am
1/26/2021 2:42am
yak651 wrote:
A motocross bike fouling plugs, what is this 1990 again??
Bruce372 wrote:
Didn't you hear, every carbed bike since 1990 ran perfectly
spimx wrote:
The last generation of carbureted 450s were great bikes.
It's your fault, you had to wear bell bottom pants
RCMXracing
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RCMXracing 1/26/2021 8:29pm
1/26/2021 8:29pm
Jeremy_Watson wrote:
Now I read that Honda has defective Injector Assembly and will replace them to correct the plug foul problem. Interesting...
What is the source of this information?
I have gone to Honda’s recall website and “0” comes up, as in no recalls. 🤷🏾‍♂️
https://powersports.honda.com/recalls
Note: Entered by model and by VIN.
mxracin
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mxracin 1/27/2021 4:47pm
1/27/2021 4:47pm
Jeremy_Watson wrote:
I just picked up a new Honda 450R, put about 15 minutes on it. Changed map settings and removed back fire screen. Restarted it and blipped...
I just picked up a new Honda 450R, put about 15 minutes on it. Changed map settings and removed back fire screen. Restarted it and blipped the throttle and I guess fouled a plug. Battery went dead shortly. I heard map #1 fouls plugs. Will it help removing the back fire screen for performance or will the ECU automatically add more fuel because of the added air? I have to buy a new plug on Tuesday and try again. I bought a lithium battery charger and battery is full currently. Any feed back?
Just a heads up.
Today Honda released a mapping update for the crf450r, RWE and x.
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hartebreak
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hartebreak 1/27/2021 5:28pm
1/27/2021 5:28pm
Crisb133 wrote:
Update it was a plug issue . Put in new plug . I went with a 9 instead of the 10 . i[img]https://p.vitalmx.com/photos/forums/2021/01/23/474535/s1200_PXL_20210123_214323770.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2021/01/23/474536/s1200_PXL_20210123_214326935.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2021/01/23/474534/s1200_PXL_20210123_214331406.jpg[/img]
Update it was a plug issue . Put in new plug . I went with a 9 instead of the 10 . i


That plug only had 2 hours on it?
Jeremy_Watson 1/27/2021 5:59pm
1/27/2021 5:59pm
Jeremy_Watson wrote:
Now I read that Honda has defective Injector Assembly and will replace them to correct the plug foul problem. Interesting...
RCMXracing wrote:
What is the source of this information? I have gone to Honda’s recall website and “0” comes up, as in no recalls. 🤷🏾‍♂️ https://powersports.honda.com/recalls Note: Entered...
What is the source of this information?
I have gone to Honda’s recall website and “0” comes up, as in no recalls. 🤷🏾‍♂️
https://powersports.honda.com/recalls
Note: Entered by model and by VIN.
I read some Honda crf450 page on Facebook and learn about it. I called my dealership and they said they already ordered parts. Keep calling and digging around for info as well...
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Crisb133
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Crisb133 1/27/2021 6:01pm
1/27/2021 6:01pm
Crisb133 wrote:
Update it was a plug issue . Put in new plug . I went with a 9 instead of the 10 . i[img]https://p.vitalmx.com/photos/forums/2021/01/23/474535/s1200_PXL_20210123_214323770.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2021/01/23/474536/s1200_PXL_20210123_214326935.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2021/01/23/474534/s1200_PXL_20210123_214331406.jpg[/img]
Update it was a plug issue . Put in new plug . I went with a 9 instead of the 10 . i


hartebreak wrote:
That plug only had 2 hours on it?
Yes sir
mxracin
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mxracin 1/27/2021 7:33pm
1/27/2021 7:33pm
Jeremy_Watson wrote:
Now I read that Honda has defective Injector Assembly and will replace them to correct the plug foul problem. Interesting...
RCMXracing wrote:
What is the source of this information? I have gone to Honda’s recall website and “0” comes up, as in no recalls. 🤷🏾‍♂️ https://powersports.honda.com/recalls Note: Entered...
What is the source of this information?
I have gone to Honda’s recall website and “0” comes up, as in no recalls. 🤷🏾‍♂️
https://powersports.honda.com/recalls
Note: Entered by model and by VIN.
Jeremy_Watson wrote:
I read some Honda crf450 page on Facebook and learn about it. I called my dealership and they said they already ordered parts. Keep calling and...
I read some Honda crf450 page on Facebook and learn about it. I called my dealership and they said they already ordered parts. Keep calling and digging around for info as well...
Unsure what parts they are ordering..? I know 2021 injectors are backordered. We tried on from my person bike into another with same results.
We have an issue with 450x at the dealership I manage. The update mapping is on the Honda IN, for your dealer to access. After uploading the new mapping on the ecu, the bike fires right up and runs like a champ.

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