Forums 🚥 PiT STOP 🔧 Hyosung Technical Help Inconsistent rpm at idle, stalling + jerky acceleration GT250 EFI 2010 Reply To: Inconsistent rpm at idle, stalling + jerky acceleration GT250 EFI 2010
Okay, I have to ask though, how is the engine compression ? Get the bike warmed up hot …. remove both spark plugs , check compression at full throttle and tell us the result. I might have a small suspicion that one of the cylinders may be a little lower than spec but we shall see after your report , because it seems like you changed everything to all new parts? Also , why not change the fuel pump as new again incase the old one of 3 years is no longer performing well, you said it was okay in the early days but now the bike is misbehaving a little bit, so it could be the pump needs changing again , usually sometimes rough running or rough idle is the pump. Try that too, and also check the TPS using service manual again to check its in spec, the idle can be affected , then reconnect the ISCV Though if you said “i removed the pipes from ISCV” and the engine idled normally, = normally on any motorcycle more in the engine to make it idle usually means the air filter is stuffed (intake system chocking) or the ignition parts are producing weaker spark causing a rich condition that includes quickly fouled up plugs
Hey Marcel, thanks for the reply!
I will do the compression test on both the cylinders at full throttle, I have never done one of those before but I found some resources online.
I thought the fuel pump was ok? I can change it again but it’s pricey 130 eur.
TPS will be checked and I will report back. As for the airbox I never changed it and don’t have a picture of it but by the looks of it looks like new.
Is there a way to test the Ignition parts? Ignition parts are: Front and back ignition coils as well as the spark plug caps?
What do you think about the mechanical ISCV solution or should I be getting a new one?
Thank you!