2020 yz450f electrical issues???

mx317

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mx317 12/15/2021 5:15am

12/15/2021 5:15am

Did you maybe get some bad gas? With the fuse blown, I would almost suspect the ECU. If you had a buddy with one like yours, I would start swapping stuff and maybe find it that way.

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TheGetFresh

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TheGetFresh 12/16/2021 7:12pm

12/16/2021 7:12pm

Some vital users have posted about an issue with the wire routing for the Wi-Fi controller under the left number plate. If the wiring is on the wrong side of the subframe it can get pinched by the number plate, and it’s apparently a common install mistake from dealers.

May not be helpful, but it’s a known electrical mistake for this bike and worth a look. Best of luck.

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DuroTools

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DuroTools 12/16/2021 9:49pm

12/16/2021 9:49pm

Johnnygunn wrote:

I have a 2020 yz450f. Has 17 hours on it, I bought it used at 13-14. Bike ran flawlessly the 2 times I took it to...

I have a 2020 yz450f. Has 17 hours on it, I bought it used at 13-14. Bike ran flawlessly the 2 times I took it to the track. The 3rd time I got 3 or 4 minutes in, landed off a jump, the bike coughed, sputtered, and died. I tried to start it for a few minutes, but it would crank, backfire, and wouldn't start. After I let it sit for 10 minutes or so it would start, idle absolutely perfectly, but as soon as I added any throttle it would die. I got it home, changed the battery out, it started and ran absolutely perfectly for about 2-3 minutes, revving it up and all. Then it went back to shit, except it would not even crank, it was totally dead... I had a friend/diesel mechanic look it over, we found a blown fuse. When replaced it started to turn over again, but it refuses to start. It's getting spark, all the wiring tested good, it has fuel, fuel pump is at least kicking on, etc.
Before I take it to a dealer and get molested, any ideas???

If "thegetfresh" response above isn't correct than I'd say take the plastics off and check all your connections, undo them blow out with compressed air and add a tad of dielectric grease and reconnect them tight. if still no bueno try unplugging sensors one at a time and see if that helps. I had a similar issue with my 250FX and this would fix it everytime. Happened like once or twice a year and had to repeat process. One of the times it I think it was the water temp sensor switch though. That's why it would only happen when the bike got hot then when it cooled down it would restart then start acting up once it got hot again. the cooler the bike the longer it lasted for. I replaced a couple sensors at a time so was never sure what fixed it but most of the time just cleaning the connections worked for me.

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Richy

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Richy 12/17/2021 4:42am

12/17/2021 4:42am Edited Date/Time 12/17/2021 4:49am

For the fuse to blow, one of a few things must happen.

A connection is bad and the power or grounding requirement from the circuit is not met by the physical connections.

A short has occurred.

Or a component has drawn more current than it safely should have, like a failing fuel pump for example, making it harder for it to work and the current raising as a result.

9 times out of 10 an even slightly iffy connection, most often grounds, can cause all sorts of intermittent or seemingly unrelated things to play up, so the above advice is well worthwhile as is the chafing / rubbing through wiring if routed incorrectly. Hope you get it sorted with a dealer-bumming.