strange noise at top end.....

[quam]

i'm no newbie to engines and bikes, but this is my first and only 2stroke so maybe this noise is something one of you guys as heard before.
it's like a very fast, high pitched rattle or click or something like that. sounds like metal on metal, or hard plastic maybe. or like a super loud, super fast salt shaker.....kinda. i think it's coming from the engine area. could be the chain maybe.

it only happens in the VERY high revs, right at the top of the power band.
have any of you guys come across this before?
i'm thinkin maybe i advanced my timing too much and it's causing detonation since my head is milled for high compression. i'm gonna try retarding the timing a little bit to see if this helps.

at first i though i must be a nut or bolt rattling loose, but everything is tight. has anybody had a messed up reed or something make a noise?
or maybe the chains too old, but i'd think that'd make noise through all parts of the power band.....
it's weird.

 

[hrdkrtazz]

To me it really sounds like you possiably Hearing socket/Chain.how do your sockets Look.preferrably the front one..If the power is still there Not running into problems.I wouldnt worry to much.But im gonna have to say your hearing the socket or chain.Would anyone else agree?I:I

 

[quam]

i thought about that, but i would assume the noise would be there at any rpm, not just in the hi rev. plus the noise goes away once i shift and the revs drop down. if it was the sprocket or chain, i would think that the noise would increase as i do through the gears....

i had another thought though. i just rebuilt the top end w/ a 0.060" wiseco but used the stock top end gaskets. could be the piston wearing into the head gasket.....but again, it wouldn't be there only in the hi revs.

 

[sdblaster]

I heard the same noise....

I just got a 01 blaster with pro cur. pipe/v3 reeds not sure on piston.I was at the desert riding it hard in the dunes and at high revs I heard high pitch tinging noises.and them just stopped....opened it up a nickle size hole in the top of the piston.going to try to flush it out....

Were do air leaks come from and why?

i'm no newbie to engines and bikes, but this is my first and only 2stroke so maybe this noise is something one of you guys as heard before.
it's like a very fast, high pitched rattle or click or something like that. sounds like metal on metal, or hard plastic maybe. or like a super loud, super fast salt shaker.....kinda. i think it's coming from the engine area. could be the chain maybe.

it only happens in the VERY high revs, right at the top of the power band.
have any of you guys come across this before?
i'm thinkin maybe i advanced my timing too much and it's causing detonation since my head is milled for high compression. i'm gonna try retarding the timing a little bit to see if this helps.

at first i though i must be a nut or bolt rattling loose, but everything is tight. has anybody had a messed up reed or something make a noise?
or maybe the chains too old, but i'd think that'd make noise through all parts of the power band.....
it's weird.

 

[CWHutzell]

its probibly the air fins on the topend vibrating

 

[blaster biotch]

YA could be airfins. do u have the lil rubber blocks stuffed on the airfins? oor u could have a broken motor mount. i had a broken mount that was hard to see on the front. and if is a ping noise that is preignition and u will explode! it is like a hammer hitting the piston. the piston is going up on copression stroke and before it gets there the mixture is ignited forcing the piston back down. not good!

 

[FLOTEK]

why guess when the plug will show you about everything youd need to know if you know how to read it .

 

[squeaklad]

i think it would be to motor mount. check them. look at it from the button of the quad to as it is very hard to see as Mrs said. i still need to get mine weilded yet. is it a big job doing that?

 

[masterblaster97]

IDK man. My quad does that too, but I thought that it was normal.

 

[stephen12091985]

mine has like a knocking noise when its a idle but goes away when im riding.it runs fine but i dont know what it is

 

[Wildcard2]

Check your plug for fine silver/greyish flakes...that would indicate detonation

 

[mjstone85]

my blaster made that same kind of sound at the top of the powerband also. the plug even looked good..... turns out my compression was high enough to require a higher octane level. i now run 50/50 110 race fuel and premium. no more "knocking" sounds at high revs.

 

[skoobyj]

my blaster made that same kind of sound at the top of the powerband also. the plug even looked good..... turns out my compression was high enough to require a higher octane level. i now run 50/50 110 race fuel and premium. no more "knocking" sounds at high revs.

Yup... My cousin in NY has same deal.

 

[blasterman87]

same thing my blasty does if i run regular octain, i put some 93 in it and no noise ....