kx250f misfires after wash

cdziekan
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cdziekan

my 2011 KX250f misfires like crazy after washing it, definitely an spark/electrical issue. I didn’t power wash it, Plugged the exhaust too. And i’ve already cleaned/ blew out most electrical connections with air. Bike ran perfectly at the track earlier. Here’s a video of how it runs, it smokes a ton too which you cant see really in the video and smells like unburnt gas
https://youtu.be/T0vNBR_dXKg
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49weasel
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49weasel 3/30/2021 3:21am
3/30/2021 3:21am
Kill switch is wet inside.
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duckdog77
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duckdog77 3/30/2021 3:48am
3/30/2021 3:48am
Throttle position sensor pretty notorious for going out on that year. Something to check into if you haven’t already.
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MotoChris
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MotoChris 3/30/2021 4:38am
3/30/2021 4:38am
Are you installing a clean air filter after washing or could the filter be wet?
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xrmark
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xrmark 3/30/2021 6:21am
3/30/2021 6:21am
49weasel wrote:
Kill switch is wet inside.
Bam. This happened to me. Got to the track unloaded and everything. Went to start my bike, started for a second and shut off. Wouldn’t start again. Couldn’t figure out the problem to save my life. Wrenches through the wall haha buddy comes over who is a mechanic, unplugged my kill switch, fired right up. Plastic bag over the kill switch every time I wash it now.

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cdziekan
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cdziekan 3/30/2021 6:57am
3/30/2021 6:57am
Thanks for all the reply’s , I disconnected the kill switch and I thought it fixed the problem for a second then it went back to misfiring, and the air filter is dry along with the air box. And i really doubt it could be the tps
kb228
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kb228 3/30/2021 7:05am
3/30/2021 7:05am
Clean all of your connections and put dielectric grease on them. If that doesnt fix it youll have to do a wiggle test and figure out where the problem is
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40acres
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40acres 3/30/2021 7:28am
3/30/2021 7:28am
Isn't this the 2nd time you've posted this video? This seems like a different story than the last thread you started, but same video.

Why do you doubt there is something wrong with the TPS sensor? Have you put a pair of meter leads to ANYTHING on this bike yet?
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49weasel
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49weasel 3/30/2021 7:28am
3/30/2021 7:28am
kb228 wrote:
Clean all of your connections and put dielectric grease on them. If that doesnt fix it youll have to do a wiggle test and figure out...
Clean all of your connections and put dielectric grease on them. If that doesnt fix it youll have to do a wiggle test and figure out where the problem is
Do not put dielectric grease on connectors. Dielectric grease is nonconductive.
My buddy just went through major headaches because of dielectric grease not being conductive.
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cdziekan
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cdziekan 3/30/2021 7:35am
3/30/2021 7:35am
40acres wrote:
Isn't this the 2nd time you've posted this video? This seems like a different story than the last thread you started, but same video. Why do...
Isn't this the 2nd time you've posted this video? This seems like a different story than the last thread you started, but same video.

Why do you doubt there is something wrong with the TPS sensor? Have you put a pair of meter leads to ANYTHING on this bike yet?
True, we believe this is possibly the same issue but we took it back to the mechanic who sold it to us and he said it was the rtv silicone in the sparkplug hole that we put in there to prevent a oil leak grounding out the spark, so he removed all the rtv and it started running normal (that's what he told us)

I mean I suppose it could be a TPS issue I just don't know, and I'm not very knowledgeable with this electrical shit so I haven't put a meter on anything yet, Id much rather work on the older bikes with carbs 😀
40acres
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40acres 3/30/2021 7:40am
3/30/2021 7:40am
cdziekan wrote:
True, we believe this is possibly the same issue but we took it back to the mechanic who sold it to us and he said it...
True, we believe this is possibly the same issue but we took it back to the mechanic who sold it to us and he said it was the rtv silicone in the sparkplug hole that we put in there to prevent a oil leak grounding out the spark, so he removed all the rtv and it started running normal (that's what he told us)

I mean I suppose it could be a TPS issue I just don't know, and I'm not very knowledgeable with this electrical shit so I haven't put a meter on anything yet, Id much rather work on the older bikes with carbs 😀
You need to download a service manual and test the TPS. It's a very common issue on that bike as said before. I know, I had one. Then you also need to disconnect and clean each electrical connection and use dielectric grease before snapping them back together. Don't just half ass shit when people on here make suggestions.
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SEEMEFIRST
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SEEMEFIRST 3/30/2021 9:52am
3/30/2021 9:52am
SEEMEFIRST
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SEEMEFIRST 3/30/2021 9:57am
3/30/2021 9:57am
Do not put dielectric grease directly on the pins or sockets.
Only around the plastic or rubber parts to protect the metal parts from moisture.
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PNWRider
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PNWRider 3/30/2021 10:38am
3/30/2021 10:38am
40acres wrote:
Isn't this the 2nd time you've posted this video? This seems like a different story than the last thread you started, but same video. Why do...
Isn't this the 2nd time you've posted this video? This seems like a different story than the last thread you started, but same video.

Why do you doubt there is something wrong with the TPS sensor? Have you put a pair of meter leads to ANYTHING on this bike yet?
cdziekan wrote:
True, we believe this is possibly the same issue but we took it back to the mechanic who sold it to us and he said it...
True, we believe this is possibly the same issue but we took it back to the mechanic who sold it to us and he said it was the rtv silicone in the sparkplug hole that we put in there to prevent a oil leak grounding out the spark, so he removed all the rtv and it started running normal (that's what he told us)

I mean I suppose it could be a TPS issue I just don't know, and I'm not very knowledgeable with this electrical shit so I haven't put a meter on anything yet, Id much rather work on the older bikes with carbs 😀
In addition to troubleshooting, I’d look for a new mechanic.
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PDUB481
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PDUB481 3/30/2021 11:13am
3/30/2021 11:13am
JUST QUIT WASHING IT
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duckdog77
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duckdog77 3/30/2021 1:12pm
3/30/2021 1:12pm
My 11’ was pretty finicky. Another check would be how many turns out you are on the choke? It’s not an idle adjustment but it does have something to do with air fuel ratio. If I remember correctly it was supposed to be stock around 32-35 turns out. My bike liked to be 37-42 depending on the day.

Been a couple seasons since I had it but that’s what I recall. Between a new TPS and that I was able to get it to run well.
Paw Paw 271
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Paw Paw 271 3/31/2021 11:53am
3/31/2021 11:53am
kb228 wrote:
Clean all of your connections and put dielectric grease on them. If that doesnt fix it youll have to do a wiggle test and figure out...
Clean all of your connections and put dielectric grease on them. If that doesnt fix it youll have to do a wiggle test and figure out where the problem is
49weasel wrote:
Do not put dielectric grease on connectors. Dielectric grease is nonconductive.
My buddy just went through major headaches because of dielectric grease not being conductive.
The pins are the main area that need this applied to them. If no grease they will corrode.

Paw Paw
SEEMEFIRST
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SEEMEFIRST 3/31/2021 12:30pm
3/31/2021 12:30pm
kb228 wrote:
Clean all of your connections and put dielectric grease on them. If that doesnt fix it youll have to do a wiggle test and figure out...
Clean all of your connections and put dielectric grease on them. If that doesnt fix it youll have to do a wiggle test and figure out where the problem is
49weasel wrote:
Do not put dielectric grease on connectors. Dielectric grease is nonconductive.
My buddy just went through major headaches because of dielectric grease not being conductive.
Paw Paw 271 wrote:
The pins are the main area that need this applied to them. If no grease they will corrode.

Paw Paw
Dielectric grease, or tune-up grease, is a silicone-based grease that repels moisture and protects electrical connections against corrosion. ... The grease does not conduct electricity, so it shouldn't be applied directly to the mating surfaces (pins and sockets) of an electrical connection.Feb 26, 2015

I guess it depends on who you ask. I was always told it was for the connections to help seal, not the conductors themselves.

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