Unknown Rattle

[Whitty21]

Since i got the bike there has been a rattle that sounds like it is comming from the top of the engine. It sounds like someone tied two pop cans tied to a string in the wind if you don't mind the metaphor. is this normal? it runs fine, great actually, and i have checked for loose parts, but have found none. I am not too concerned cause it isnt very loud and it isnt broke yet, but any ideas

 

[2g00d4u]

try tightening all the bolts holding the engine itself into the frame and any other bolts in the area.
gotta start with small things.

 

[fsuroxu]

Have you done a plug chop to see if your jetting and carb are set right? Sounds like slight detonation. Could do that for awhile and then one day, KABOOM! Check it out!

 

[Whitty21]

How do you do a plug chop, and what is detonation, not a big engine buff

 

[xJust_Causex]

could also be the baffle in the stock head pipe, they are known to come loose at time.

 

[Brute71]

there's a thread on here on how to do the plug chop (in a nut shell, its checking the color of the insulator in the plug) and detonation is the pre ignition of fuel

 

[Whitty21]

I just checked my plug, it was brand new about 3 of riding on it now, after sittong for a couple hours today it was still wet and i think if i were to clean it up it would look brand new, i wouldn't be lean if all this was happening right?

 

[Whitty21]

also glad to see another canadian on here 2good4u, represent!!!

 

[Whitty21]

anyone? 15151515151515151

 

[xJust_Causex]

If it is still wet it could be a tad rich, but just looking at the tip of the plug is going to tell you basically nothing. basically you need to warm the bike up on an old plug, then swap it for a new plug and run at WOT through 6th gear, then pull in the clutch, kill the motor and coast to a stop. Then you need to pull that plug and switch back to the old plug to get you home. When you can take a hacksaw and cut down the threads to allow you to see the base of the insulator. You should see a band roughly 2mm high and a chocolate brown color, that means you jetted just right. A band higher than that or one that is a different color/missing completely means you need to bump up a jet size or two as you are still lean.

 

[nd jat]

A ruff gauge of the jetting you don't need to hack a spark plug to see. If it's black and sotty looking then your rich if it's white or ashen color than your way to lean, brown or dark brown idealy is good (like the crust on bread).

 

[Whitty21]

i am gunna do that when i get a chance

 

[nd jat]

Just a thought do you have rubber on the fins of the jug like between the fins? That could be where the noise you hear is coming from, if there is no rubber dampeners on them.

 

[Whitty21]

dont understand where you are talkin about

 

[nd jat]

the top of the cylinder there like inch by inch in a row

 

[xJust_Causex]

Mines jetted rich, but my new plugs where still white/grey when I pulled it and it has 2 or 3 good rides on it, and if you have seen a plug used in a chop they will still be white except where the band is suppose to be. If you run one long enough for it to start building up carbon and get brown, you could actually burn your motor up first. I doubt it is the rubber fins, I have seen bikes without them and they don't have rattle issues. When exactly is it rattling, is it at a certain speed, certain motor rpm. I still say it could be the baffle in the head pipe.

 

[super noober]

Mines jetted rich, but my new plugs where still white/grey when I pulled it and it has 2 or 3 good rides on it, and if you have seen a plug used in a chop they will still be white except where the band is suppose to be. If you run one long enough for it to start building up carbon and get brown, you could actually burn your motor up first. I doubt it is the rubber fins, I have seen bikes without them and they don't have rattle issues. When exactly is it rattling, is it at a certain speed, certain motor rpm. I still say it could be the baffle in the head pipe.

i like the baffel in the head pipe suggestion, and i have no rubber insulators on my motor and no rattle

 

[Drifz1]

maybe its the chain rollers?

 

[Whitty21]

Chain was my first thought, cause it is pretty loose, but it doesn't sound like that area, the baffle sounds right too, cause i still (for some unknown reason ) have a stock pipe. I am gunna do a plug chop, maybe today, if i got time, but soon anyway, i will keep you updated

 

[Troyaughenbaugh]

It could just be the normal tapping/rattling sound that the normal running blaster makes. You know when the piston is moving up and down during low rpm's like while idling.