New area for weird noises?

Discussion in '2-Stroke Engines' started by Vistaman73, Aug 8, 2010.

  1. Vistaman73

    Vistaman73 Member

    I was thinking, maybe we could add on to the troubleshooting section for weird noises. We could make a guide for what noises are what. It would help someone get nearer to a solution. We could make sound clips of each noises too. How 'bout it? BTW: I myself am having a weird sound when I'm going at speed and let off the throttle I get a LOUD sound like a metal rattle snake but if I pull in the clutch it goes away. Like engine braking, that's when it makes the noises I have no idea what it is? :whistling:


  2. skrufryder

    skrufryder Member

    Strange noise

    so are you runing a two stroke with a pull starter or a 4 stroke?
  3. GearNut

    GearNut Active Member

    Check your engine drive chain tension. It could be too loose and surging.
  4. Vistaman73

    Vistaman73 Member

    It's a 2 stroke no pull start, my chain is tight and true. It's really weird how loud it is like a metal rattle snake but as soon as the clutch is pulled in, it goes away. I can't find out exactly where it is coming from but its fast paced so it must be from the engine itself. It only happens when im cruising on the road not when im going really slow. I noticed it was hard to put on the chain that came with the grubee (410 I believe) onto the drive gear of the RAW engine. Also, I got a sprocket from jim but it was too wide for my chain, it looked like it was just as wide as the drive sprocket but I was able to get the chain on the drive sprocket by use of a hammer. LOL It fit but it was snug, I was thinking, if it IS a 410 chain maybe I should get a 415 chain and put the wide sprocket on the wheel? Could that be it?

  5. GearNut

    GearNut Active Member

    How recently have you re-greased the transmission gears, or the clutch hub bearings?
  6. Vistaman73

    Vistaman73 Member

    The engine is brand new. I greased the gears yesterday which was the first day of it running. Honestly, I have been looking around here alot and have never heard a problem like this. Everything is new and greased very well. It's not a grinding noise but more of a rattling noise. I'm amazed how no one commented on my suggestion. LOL.
  7. GearNut

    GearNut Active Member

    Suggestion? If you are referring to the chain size, the Manic sprocket is sized for a 415 chain. Now that I re-read your post :eek: I bet that the 410 chain is the root of your noise.

    When I switched to the Manic rear sprocket I had to swap out the engine sprocket with a spare I had. The 415 chain would not even come close to fitting on the original engine sprocket.
  8. Vistaman73

    Vistaman73 Member

    OK, yeah I had to tap the chain to get it on the drive sprocket, but it fit and worked fine. I meant the original reason for posting. Making a new section with a guide to weird noises. My problem sparked this idea of mine. Is it dangerous for me to run it like that? I've been without a MB for all summer, and now I got it running I don't want to have to go out and buy a chain. Also I have absolutely no money and can't afford a new chain. LOL

  9. GearNut

    GearNut Active Member

    If the chain will fit smoothly around the sprocket without any binding what so ever and (*this is an important and*) the rollers fit all the way down into the valleys in between the teeth, you should do fine. If the rollers will not fit all the way down into the valleys at any given spot around the whole sprocket and the chain is riding up on the flanks of the teeth
    you risk bending the teeth, ruining the sprocket and throwing the chain.
    Inspect it carefully.
    The width of the sprocket teeth fitting between the inner plates of the chain is where you may find trouble.
    A 410 chain is 1/8" wide between the inner side plates.
    A 415 chain is 3/16" wide between the inner plates.
    You may end up having to do your own "machining" to thin the sprocket teeth to get it to fit correctly. Not impossible but you will have to get creative and be careful to not render the teeth too thin.
  10. GearNut

    GearNut Active Member

    As for your thread idea, it is a good one but, these engines make so many weird noises it would get interesting to say the least.

    "My engine is making a clickety bap noise. What could it be?"
    Sound recording would almost have to be a requirement.