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I ran the battery on my Husqvarna FC350 down in the pits to the point where it would just barely turn the engine over. I had some friends push me so I could bump start my bike. It fired up but then died two seconds later. They pushed me again and it fired up again, but then it died almost instantly. They tried one more time with the same results‚ then my pushers gave up. Since it started, why wouldn’t it keep running?
Technically, it should have kept running once you bump started it, but you let the battery run down too low. The battery didn’t have enough power left to operate the fuel pump, and even though the engine started momentarily, it didn’t generate enough juice to get the fuel pump up to the proper pressure. Thus, it would start and die. Perhaps if you had had a longer hill, you might have been able to keep it purring long enough to get the electrical power you needed to get fuel to the top end, but this will rarely happen under human power. If you had a spare battery, you could have started the bike easily while using the choke, which we assume you didn’t do the first time you ran the battery down. Additionally, you could jump start (as opposed to bump start) your Husky with jumper cables to your truck’s battery (the car doesn’t need to be running). The MXA test crew carries a spare KTM/Husqvarna battery in the bottom of our toolbox to fix these problems, and then we put the drained battery on a trickle charger (and it becomes the spare battery).
Do not grind away on the electric start button. Never press it for more than 3 seconds. If it is cold outside, warm the battery up by pressing the button, without starting the engine, to get the fuel pump to run. When the fuel pump runs, the battery gets warmer — and, as it gets warmer, the voltage on Husky and KTM’s iron-phosphate batteries goes up. Then, press the button again, but only for 3 seconds. If it’s going to start, it will start on the first or second four-cycle rotation — going another 100 rotations won’t make any difference. Choke it if need be.