You mentioned the fuel pump, fpr and relays were swapped. Did this problem occur before or after any or those changes?
Help! Starts Cold, Won’t Hot
When my 2004 RC51 is cold it starts every single time. When I go for a ride and I shut it off then try to start it, the fuel pump won’t kick on. 12v is at fuel pump relay brown wire. Then soon as the bike cools back down starts right up. This happens every single time. It’s like the fuel pump won’t run when the bike is hot. From a cold bike I can go on an hour long ride no problem long as I don’t shut it off. Unless there is some PFM going on I’m stumped. Fuel pump was recently replaced along with FPR. Relays have been swapped. No change. Ordered a new fuel pump, but I’m not sold that’s the issue. Thanks!
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No had been fine. Previous owner, who is a friend, did the replacements. I hadn’t messed with anything before this started.
Do you hear the pump prime when you try a hot start?
No. Pump doesn’t prime when the bike is hot. After I let it sit for an hour it will start again every time. I can only hear a click in the tank when it won’t prime.Do you hear the pump prime when you try a hot start?
Pump sounds like a cheap replacement. As it gets hot, the motor is locking up. The reason why you can keep riding when hot is because it’s already turning. But the moment it has to start from a dead stop, the motor isn’t strong enough. I’ve seen this on many vehicles as well.
That was my theory when I ordered the pump. Kinda like servos when they lock up and you have to tap them with something to get them spinning again. It’s just so consistent and easy to make happen again wondered if there was some thermal protection circuit that I didn’t know about. Thanks for backing my theory. I’ll just go ahead and swap the new pump in. 👍🏼Pump sounds like a cheap replacement. As it gets hot, the motor is locking up. The reason why you can keep riding when hot is because it’s already turning. But the moment it has to start from a dead stop, the motor isn’t strong enough. I’ve seen this on many vehicles as well.
Hmm. There could be a protective circuit. But even if there was, it would still be based off of resistance at the pump. Just my theory. I’ve had this exact same situation happen with hellcat pumps.
What is the capacitor looking thing? The wire at the base is pretty bad. It’s the black and brown wire going in.Pump sounds like a cheap replacement. As it gets hot, the motor is locking up. The reason why you can keep riding when hot is because it’s already turning. But the moment it has to start from a dead stop, the motor isn’t strong enough. I’ve seen this on many vehicles as well.
Lol, I’m not quite sure. But that brown wire looks toast.
Think the pump fixed it. Went on a decent ride and it started right up after she was hot. Will go for a longer ride tomorrow 🙌That was my theory when I ordered the pump. Kinda like servos when they lock up and you have to tap them with something to get them spinning again. It’s just so consistent and easy to make happen again wondered if there was some thermal protection circuit that I didn’t know about. Thanks for backing my theory. I’ll just go ahead and swap the new pump in. 👍🏼
Where did you get the new fuel pump from?
Quantum Fuel Systems. Nice kit and shipped fast!Where did you get the new fuel pump from?
BTW, the capacitor looking thing is a resistive fuel level sensor. That’s the component that will send the low fuel warning light to the dashboard.
I've started having a similar issue.. plenty of fuel and the pump will prime but won't start warm.. just started today. Yesterday I gave her a bath, today she don't start over 110°
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