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Joined
2/11/2015
Location
La Place, LA
US
NoMuff2Tuff
8/19/2019 6:54am
8/19/2019 6:54am
Edited Date/Time
9/25/2019 4:24am
Posting for a friend. Bike ran fine all day at the track. Next day bike was started on the stand was running fine for a minute then all of a sudden started running poorly and popping/backfiring. Bike was never washed and still had same fuel from day before. He changed plug and no help. He brought the bike to my home shop, I disconnect the fuel line from tank, connect a long rubber hose to a bucket and kicked over the bike, no fuel would pump out. I pulled the tank and ran direct 12v and the pump ran and pumped fuel no problem, connected a gauge and would get about 45 psi. I did noticed when the pump wasn't running a small amount of fuel would still gravity flow and I always thought no fuel should flow out the tank/pump when the pump wasn't running. I'll get back to this later. Put the tank back on the bike and the bike started and ran fine for about 30 seconds then started to cut out and pop again. Next was disconnect fuel pump wires and as the bike is being kicked over the voltage will start rising and get up to about 9-10 volts. Is this not enough voltage possibly? Re started bike and same thing, just to get the bike started fuel needs to be dripped into T/B and once running its doing the same thing. Since I noticed some fuel will gravity feed, I"m wondering if its just getting enough fuel gravity flowing through the injector "if that's even possible" to run but not enough causing it to be lean and pop and back fire?? Double checked cam timing, dead on. Next thing I'll try is to run direct 12 volts to fuel pump and see what happens. If it happens to run fine this way what could be causing the fuel pump not to stay running while on the bike?? Bad voltage regulator, bad condenser? Has anyone had a kxf250 run poorly and figure out the issue? Does anyone know what the tip over sensor shuts off if it is bad? Trying to get a service manual from another guy to help troubleshoot. These bike can be frustrating lol
To me it seems like its starving for gas. Id replace or clean the injector and see if it gets better. Replace the fuel pump afterwards.
Paw Paw
The Shop
Paw Paw
Post a reply to: 2018 Kawi kxf250 running bad/popping