Knocking Noise on the 300ex

[thursday]

theres a light knocking noise coming from the cylinder on my 300, im thinking its the valves(loose)....ne ideas? appreciated, thanks alot

[ny300exrider]

sounds like the valves need some adusting

[FBRacing80]

What kinda gas did you put in it? Im not the greatest with 4 strokes but if its anything like a car some of them the valve's rattle when you put cheap gas in them.

[Scott-300ex]

actually, the gas deal, thats when the motor pings, it is because of the products in the kind of gas or and mostly because of the octane rating, for example, if you put gas with an octane rating of 86 in your car and it requires 93, then you will have detonation, from there making 2 explosions in the combustion chamber and the coliding together of the two explosions makes a sound that you can hear called a ping, the 2 explosions are from 1 of the spark plug and the other 1 from the heat in the combustion chamber. Now when you put 93 octane rating in the vehicle, when the gas enters the cylinder, it will wait to be fired untill the spark plug ignites it and it will not/should not fire from just the heat of the engine. This is true for the octane rating of your car.

to the guy with the problem, i would say that it is your valves, or valve springs, also could be your rocker arms, if it is basically like a light ticking noise i would bet you it is in your valve train. well, good luck

[TRX300X]

If it's a fast ticking sound then it's your valves, if it's more of a rattling sound then it's your pistion getting sloppy in the bore.

[Butters]

like alot of the others have said it most likely is the valves. mine did that and all i needed to do was adjust the valves.