ktm/husky fuel pump issues maybe? chime in ASAP! pulling my hair out.

adam8781
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adam8781
Edited Date/Time 7/20/2019 8:29am
is this my fuel pump going? just did topend today


2017 fc350. 79 hours maintained perfectly every 5 hours. fresh pro x piston the oem looked good bit polished on skirt no big deal.

Assembled it fired up after a bit of a crank, ran smooth. (assumed it was fuel line refilling)

shut it down, topped up coolant took it for ride outside garage everything seemed fine got it nice and warm for a heat cycle.

Shut it off, went to start it again, turns over and over and over but wont start, almost starts but wont, sits for 20 minutes. than it fires up perfectly. warmed it up on stand in garage. shut it off. now its back to cranking forever but not starting.

Valve clearance is .10mm intake .13mm exhaust (within spec i do believe)

any ideas? this my fuel pump? what am i missing here?
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kb228
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kb228 7/19/2019 3:56am
7/19/2019 3:56am
I had this issue on my kx450, turned out to be a bad coolant temp sensor. When it got hot it wouldnt deliver the proper fuel ratio.

Your problem is stemming from the bike being hot. If the fuel pump was bad it would be doing it hot and cold. Could be the pump, but based of my experiences i lean towards something else.
yzrider53
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yzrider53 7/19/2019 8:02am
7/19/2019 8:02am
What's the idle rpm? They don't like to fire up when hot if idle is too low.

Any blink code?

If you think you have a pump issue you'll need an inline gauge to test pressure while the bike is running.
aees
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aees 7/19/2019 11:41am
7/19/2019 11:41am
I would look for the problem in what you just messed around with. Possibly cam/chain in wrong position.

Fuel pump you can just disconnect the quick release from the tank, and put a screwdriver up towards the tank into the hose and push the starter and see if you get blasted in fuel. You also hear the pump going.

If the fuel pump was going out, or if there was a leak inside the hose or filter in the tank the bike would run but poorly and would be most noticed when revving it up.

Would also check the plug to see if anything happen while dis/assembly.
CarlinoJoeVideo
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CarlinoJoeVideo 7/19/2019 9:00pm
7/19/2019 9:00pm
I’ve heard when people remove the plug cap, it cracking and the long part of the spark plug cap cracking and arcing against the inside of cylinder. Don’t think that’s a head related issue though.

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Tuzzo123
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Tuzzo123 7/20/2019 8:29am
7/20/2019 8:29am
I know this is been played out, check the electrical connections behind the front # Plate. I had a broken wire on my sons KTM 250 SXF and it was the same symptoms. Worh a look before you tear it down.
adam8781
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adam8781 7/21/2019 7:44pm
7/21/2019 7:44pm
thanks for your answers, i took topend completely apart again to see if i missed something, cam timing was perfect, valve clearance perfect, no valve contact with piston or anything like that. put it all back together and it runs perfect now, all i can think of is a loose connection. runs perfect now very strange.

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