Vibration issue on my bike project

[versionhorr0r]

Been reading a ton but figured it's time to jump in and share one of my current builds. I'm a longtime minibike fan and recently started restoring a 1978 Coleman Trailmaster with a Lifan 110cc semi-auto engine. Right now I'm troubleshooting a weird vibration at mid-throttle , could it be the motor mounts or chain alignment?

 

[Thecompactor]

Could be both I think, but I'm leaning more toward the chain because if it's the mounts you'll notice the vibration at every speed and throttle position. I'm guessing you've tightened everything?

 

[oldking56]

That vibration at mid-throttle could definitely be caused by loose or worn motor mounts or a misaligned chain. Its worth checking that the engine is securely mounted and that the chain is properly tensioned and aligned, as even small deviations can cause noticeable vibration on a lightweight minibike like the Trailmaster.