350sxf Fuel System Troubleshooting

CR23
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21
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4/16/2024
Location
tallahassee, FL, USA

Hope someone can offer some help.  Gets expensive just changing out parts!

2019 350sxf , 57 hours, valves checked and in spec, clean air filter, clean fuel filter (small one), fresh gas every ride.  No glaring problems.

Two rides ago, bike coughed and died, randomly while I was riding, twice.  Restarted and ran the rest of the day.  This past w/e I was getting ready for the first ride, bike started and idled  on the stand for 15 seconds then died.  Took a bit to restart, but did the same thing 3 or 4 times.  Cranked and quickly tried to give it throttle, and it died.  After a number of attempts I felt like the battery was getting drained because it was slower turning over.  Checked and voltage was slightly low, so I quit trying and loaded up.

Two days later, installed new battery (fully charged).  Changed plug, dumped fuel in tank and put fresh in again.  Starts, runs 10-15 seconds, dies.  As it starts getting hot, it gets harder to crank.

I've double checked grounding and other connections.  I'm about to change out the in-tank fuel filter.  Will a clogged in-tank allow it to crank and run, then die?   I've seen video of some with low fuel psi that still ran ok, but just down on power.  I also looked for bubbling in the tank (cracked FF), but didn't see any.

If the filter doesn't solve it, I assume the next step is a full Fuel Pump replacement?   I checked pressure and it was right at 50 psi. (static)   I had a pump fail on an 2018, but it just died.  No cranking.

Any other suggestions are welcomed and appreciated.

CR23

 

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charlie68
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6/28/2019
Location
North Windham, CT, USA
8/1/2024 12:13pm

Have you cleaned or replaced the injector?

dansfx
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8/18/2023
Location
Greenville, NC, USA
8/1/2024 12:30pm

The plastic fuel filter in the tank is know to crack on those models and cause issues like that.

Also, I've seen a bad spark plug cause a 350 to very similar issues to what you are describing.  

CR23
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Location
tallahassee, FL, USA
8/1/2024 12:55pm

No, i haven' touched the injector.  Is there a way to test it?  Battery on the bench?  

Just took the fuel pump out of the tank.  Its a 6 year old bike, but sat for a few years in my friends shop.  The filter didn't seem to be cracked.  It does look dark, so not sure how dirty it really is.   New filter will arrive tomorrow.  Pump spins up and sounds fine when tested.   I also have another new plug coming.  The one I put in it was in the tool box for years.  It looked new, assumed it was.

Thanks!

8/1/2024 5:08pm

Check inside your spark plug cap for cracks

The Shop

sandman768
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8116
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3/21/2014
Location
Saratoga Springs, NY, USA
8/1/2024 5:23pm

Coils can go bad, spark plug cap, fuel pump,  oem ecu? I had similar symptoms with a bad Vortex ecu…

CR23
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4/16/2024
Location
tallahassee, FL, USA
8/2/2024 4:27am

Well, I do have a Vortex.  After I try the other stuff, I'll plug in my OEM ECU.    Thanks

sandman768
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8116
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Location
Saratoga Springs, NY, USA
8/2/2024 4:45am
CR23 wrote:

Well, I do have a Vortex.  After I try the other stuff, I'll plug in my OEM ECU.    Thanks

Try your oem ecu, I had sent my Vortex to Twisted to get remapped for my 24 350 and they notified me it was bad & Vortex had a recall, I got a new Vortex for free & just had to pay for mapping. I sold my 22 to a friend with the stock ecu, he has not had 1 issue. Its very dangerous when your engine just stops dead, Happened to me just before a big jump…. 

kijen
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1228
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10/1/2010
Location
Jacksonville, FL, USA
8/2/2024 10:35am

Had 19 450sxf same thing, changed a few fuel and electrical parts, gave up took to a dealer, it was a bad sparkplug, ran great afterwards so didn't argue or if it really was.

..

CR23
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21
Joined
4/16/2024
Location
tallahassee, FL, USA
8/2/2024 2:07pm

OK.  Due to inner child and wanting to ride tomorrow....I put in a new fuel filter and spark plug at the same time.   Buttoned it up.  Runs like a champ!

IMO, I'm leaning more toward the spark plug.  It wasn't cracked.  Although the fuel filter was cloudy, it was full of fuel and I could blow air through it.  Maybe it was not allowing enough flow to keep the pressure up, but IDK.   The first plug I pulled out looked old, the plug I replaced it with was used but in the box in by tool chest.   Normally wouldn't take one off and not pitch it, so I assumed....

I think the new battery helped.  It cranks immediately.  Seems like its idling a couple hundred rpm higher, but didn't write down the last reading.

Thank you for all the suggestions!  Hopefully someone finds this later and they get a little value.

 

CR23

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