Reving out

[Callum2461]

Ok so this is the 3rd time I have been on here after countless problems with my brand new 2 stroke 70cc bike. Now when It gets up to a certain speed, I don't know let's say 25km/h, it revs out (makes the same noise it makes when It reaches it's max speed) it's like a scratching sort of noise like when I go too fast and have to back off the throttle. Could anyone please give me a diagnosis??? Thanks for any help

 

[Fabian]

it's like a scratching sort of noise like when I go too fast and have to back off the throttle.

Engines are not supposed to make scratching noises.
Maybe it has something to do with the fact that the engine was revved out excessively.

It's a problem that only money can fix.

 

[Fabian]

Ok so this is the 3rd time I have been on here after countless problems with my brand new 2 stroke 70cc bike.

Count yourself lucky that you've only been back here 3 times.
If i were to tell my story, we'd be talking for the next 2 months.

 

[Deleted member 12676]

take off the clutch cover to look and see if anything is abnormal (loose screw, etc).
make sure your chain has the right tension. when too loose it can hit the cases at the top of its entry space. that only happens at top revs

 

[Callum2461]

Thanks everyone for your help. My chain does look a bit loose so maybe I will tighten it to see if that helps.

 

[wheelbender6]

Like Jag said, the scratching noise usually indicates a clutch issue. Something in the clutch needs to be tightened or adjusted.

 

[HeadSmess]

i ignored my scratching sounds until the crank gear screw popped out the side

from the sound of the post... your flower nut has come loose, is rubbing, and the clutch is slipping slightly just to add to the drama...