Posts: 417
Joined: 8/17/2017
Location: Miami, FL USA
What's up everyone, thought I would come here for some help. I have a KTM 250 SX-F factory edition, just had entire top end and crank replaced, but now bike warms up for about 10-20min, perfectly fine sounds great then you try start and within a couple of seconds it bogs out. Any idea what it could possibly be?
Posts: 1731
Joined: 8/25/2015
Location: Mansfield, OH USA
Probably something to do with letting it warm up for so long. Start it, put your gear on and ride it. Engine heats probably throwing the air temp sensor off.
2009 Kawasaki KX450F
2009 Kawasaki KX250F
2002 Suzuki GSXR 600
Posts: 417
Joined: 8/17/2017
Location: Miami, FL USA
No I'm saying rode it for 10min, then this problem came up and now it starts for like 10sec then bogs out
Posts: 1731
Joined: 8/25/2015
Location: Mansfield, OH USA
Fuck man could be a bunch of shit. Bad fuel pump could cause it. Runnin that pump gas in these finicky race bikes is no bueno. Shits got dirt in it.
2009 Kawasaki KX450F
2009 Kawasaki KX250F
2002 Suzuki GSXR 600
Posts: 6677
Joined: 11/30/2013
Location: Portland/Los Angeles, CA USA
Any codes flashing in the light behind the number plate?
-Dirty In-line fuel filter?
-Fuel pump bad
-Did you disconnect any of the grounds to the frame?
-Bad fuel?
-Check the plug boot for cracks, sometimes the rubber splits when you insert them because the fitting is so tight. This will cause them to arc off the engine.
Posts: 417
Joined: 8/17/2017
Location: Miami, FL USA
It doesn't start for 10 seconds. Shuts off after you rev it. Or ride it and let off gas to turn around. Starts right back up. Fuel filter is not clogged. Didn't have one before so it's a new one. No codes flashing
Posts: 6677
Joined: 11/30/2013
Location: Portland/Los Angeles, CA USA
I’d try to find someone with the same bike and start swapping parts.
First I’d try their fuel tank. Also check your spark plug boot for cracks as mention above...
Posts: 393
Joined: 12/26/2014
Location: Fruita, CO USA
Posts: 155
Joined: 9/25/2016
Location: Golden, CO USA
Check the part of your subframe where the seat rides on in the back where the battery grounds. I had it crack and it did some weird shit because the battery couldn't ground.
Posts: 11
Joined: 4/28/2017
Location: IN, USA
Anyone ever figured out the above?! I literally just ran into the same issue. It started with not wanting to idle and left me stranded(battery died from restarting getting back to the van)#needsakickstarter. Next time out I put brand new race gas and battery had no issues first race of 2018 so maybe 30 min run time. The issue came back, went out to practice and the idle and power was hit or miss but got better with time. Thought the injector was cleaning itself out. Went out the last time (today 4/4/2018) and the bike ran great the start of the day. Then an hour later had weird bog issues (half a lap) then FINALLY died on me and won't start! This is driven me nuts. My plan is to check the Throttle position sensor tomorrow. Then check spark plug (new from winter maintenance). If I don't find anything I plan on sending it to the dealer. I think it may be fuel pump given that I have already changed the fuel filter on the bike this winter as well.
Posts: 6677
Joined: 11/30/2013
Location: Portland/Los Angeles, CA USA
Wasn’t there a rectified problem with the 250SXF? Seems like it has something to do with heat. I’d be looking at electrical items. Maybe the condenser, voltage regulator or coil?
Another thing I’ve heard is when you pull out the spark plug cap if your not careful you can actually rip the rubber and it was arc against the cylinder.
Posts: 679
Joined: 1/11/2017
Location: CAN
Posts: 11
Joined: 4/28/2017
Location: IN, USA
CarlinoJoeVideo wrote:
Wasn’t there a rectified problem with the 250SXF? Seems like it has something to do with heat. I’d be looking at electrical items. Maybe the condenser, voltage regulator or coil?
Another thing I’ve heard is when you pull out the spark plug cap if your not careful you can actually rip the rubber and it was arc against the cylinder.
I am not sure about the rectified problem? But I am breaking out the fluke meter now. I will start checking voltage and ohms per manual now. Thanks for the ideas!!!!
Posts: 3345
Joined: 4/3/2013
Location: Benton, LA USA
Posts: 6677
Joined: 11/30/2013
Location: Portland/Los Angeles, CA USA
Paw Paw 271 wrote:
Fuel pump/ delivery issue.
Paw Paw
Some 2016s had a fuel line that was kinked in the tank. Google that issue, it’s easy to check and won’t cost you anything.
Posts: 11
Joined: 4/28/2017
Location: IN, USA
