Mystery Noise

[mower_man]

What is the knocking noise made by the engine at idle? I have listened to several Blaster on Youtube at idle and they all seem to make the same noise at idle.

 

[REEDracing94]

its the spark plug

 

[Valhalla]

normal engine noise. it has to do witht eh way the soundwaves in the expansion chamber come back into teh motor. the expansion chamber is tuned to reflect sound back into the combustion chamber at a certian RPM. once you are under that RPM its out of sync and makes all kinds of weird noises. kinda like pre-detonation knocking. noting to worry about though. its the blasters way of telling to you go faster.

 

[REEDracing94]

i thought it was there is 2 diff plugs u can use and the one dosnt do that

 

[mower_man]

Cool. Guess I'll just have to go fast!

 

[ruthless_one3k]

mine does it too, I think vallhalla is on the right track

 

[mower_man]

Using the B8ES plug.

 

[REEDracing94]

o must be what vallhalla said then

 

[cirame1]

im using a ngk br8es i think or sumthin like that wats everyone using for plugs and is there an advantage of using a dif plug on stock motors with exhaust and carb and reeds? i kno with hotter motors its good to use colder plugs but is anyone using dif. plugs on stock piston motors and wat r ur benefits?

 

[blaster biotch]

a stroker crank really makes some ticking noises. i run a br8es. the higher the # the hotter the plug, never had a problem with the br8es. now if u hear a slappin noise that isnt good. that is ur piston skirt slapping the cylinder on the compression stroke ans it will bust the piston. this happens when the rings are to far gone and makes a big mess!!!

 

[Valhalla]

brand new unmodified motors make this noise as well.

 

[specialized7]

i almost think i hear a slap on mine how hard is it to do a rebuild , what would i need?

 

[pportera]

the higher the # the hotter the plug,

Higher the number 8, 9 is COLDER lower number 5,6,7 Hotter.