1984 Honda 125m knocking in third gear

[dmo82]

I got my 125m three wheeler running that I rode as a kid. Hasn't been ran in probably 15 years. When I was a kid I rolled it, Ever since then it started to knock when I put it in third gear. Any ideas what it could be? Where I would start with problem solving. I have a video I can upload of the sound if that would help.

[dmo82]

https://youtube.com/shorts/1bZsffezz5A?feature=share

here is the video of it knocking in third gear and then i shift to 4th and it stops

[shortline10]

If it’s only having the issue in third gear then you must have a chipped tooth or bent shift fork . Either way it’s not an easy fix . I would say flush the oil , make sure there’s no metal debris and run it as is .

[dmo82]

any idea where I can purchase this part? I'm looking for it but want to make sure I'm getting the right thing.

[shortline10]

Best bet is eBay . Either buy a complete known good bottom end or a complete transmission with shift forks .