Every year my 2008 Suzuki Bandit GSF1250S ABS, Bandit for short, has some throttle issue when the weather drops. This morning was a particularly difficult ride to work, and I was sure that I was going to crash. The bike hesistates at low RPMS, and it being a liter bike, as a really aggressive powerband. It’s really easy to accidentally launch the bike when you’re not intending to. With anything related to hesistation, it’s either fuel, air, or spark. With modern ECU vehicles, there’s also a sensor suit for fuel, air, exhaust, etc. Trying to diasnose this issue isn’t going to be easy, as I think there’s another sensor issue that is also aggrevating the issue, and making the hesistation worse than it actually is.
When working on vehicle issues, you have to think logically, and try one solution at a time. You should also work from cheapest and easiest solutions, to most difficult. A solution that requires only an air filter change should not be started with a complete engine rebuild.
As of now, I am going to start with the fuel and air. I already changed the air filter, and that did not affect the issue at all. I am going to run the bike out of gas, and fill it with a ethanol free fuel, and see if that does anything. If not, then I will begin changing or adjusting parts. I will possibly have to order tools, a throttle body tool for measuring the vacuum of the throttle body injectors is an example. I don’t really expect this issue to be fixed before the summer months, when this issue goes away. However, it will set me up for next winter, where if it is not finished, I can seriously look at some deep issues the bike potentially has.