There is a faint knock noise that I can hear when my bike idles and I cant figure out what it is. When I rev the engine, it goes away. Power seems normal and the bike isnt smoking or anything. Any ideas? Thanks.

 

cam chain tensioner?

 

What octane fuel are you using?

 

i think mine does that too. what exactly do you mean by a knocking sound? i use the high stuff at the gas station. 93?

 

bro you bike does not need anywhere NEAR that high of octane.

it needs 87 octane only!!

read the damn manual, you are throwing money away and losing horsepower!

 

over here in the UK we can't get petrol under 95 octane, the high octane is normally 98.

 

Found this and thought it was intesting, it seems to think that higher octane fuels prevent pinking.

Knock" and its relative, "Detonation", occur in the engine's combustion chamber under conditions of extreme heat and compression, and a weak mixture or low-octane fuel. During the engine's compression stroke, the pressure of the air / fuel mixture is raised, which increases its temperature. This is good, because it makes it easier to ignite. However, when the pressure and temperature get too extreme "detonation" or "knock" can occur.
Detonation occurs when the spark plugs fire and the flame burns too quickly, resulting in the air / fuel mixture detonating, rather than a controlled burn. Also known as "pinking".
"Knock" occurs when the air / fuel mixture has its temperature and pressure raised to the point where it spontaneously ignites in the combustion chamber without the aid of a spark.
Knock is the phenomenon you're most likely to hear about. Both these problems can result in severe engine damage if allowed to occur unchecked, and both can be helped by using a fuel with a higher octane rating, as it will be more stable, and less susceptible to spontaneously ignition. Contrary to what a lot of people seem to think, a higher octane fuel does not necessarily equate to greater engine performance - rather, it allows the engine to run at hotter temperatures and greater compression ratios. This can allow an engine to generate more power in a given period of time, thereby yielding greater performance.

 

well, i dont have a manual yet. it didnt come with it and i have not ordered it yet. why is that so bad? i just figured its better.can you explain why lower octane gas is better? am i hurting it with the higher?

 

meh, spending the few extra pennies for medium or high grade gas doesnt seem like "throwing away money". Any loss in power shouldnt be noticeable unless you're on a dyno or something. If you're uber paranoid either way, use mid grade and listen for pinging.

 

its a bike it will make noises from time to time unless you are hearing some loud knockin that other ppl notice worry, if not just ride .and no nothings wrong with puttin high octane gas in the f3 the manual says 90 n above ,but you can use regular which you wont see any difference .