Hi all i have a 1999 335 and have noticed a engine noise that sounds like spark knock. The noise is at first throttle and sounds like a single detonation.It only does it when starting from a dead stop.Is anyone else experiencing this problem and if so can you tell me if its anything i should be concerned with? Thanks in advance for the help?

 

Go to the next higher level of Octane.For example,if you are currently using 87 octane,run it[gas tank] almost empty,than refuel with 89 Octane fuel.If the noise is still present,repeat what I just told you and use 92 octane on the next fill-up.One of these two tries should correct your problem,remember,once you find the correct Octane for your quad,you need to stick with it.====Bill