Yamaha TRX850 Enthusiasts Forum

So, my brother has been borrowing my father's TRX and recently has ridden it low on oil. When he realised he babied it to the nearest servo and topped it up with oil. It seems though that the damage may have already been done. I am guessing from the story, the sound, and my research that he has done the big- end bearing, but can someone please confirm/deny this? I have attached a video. It idles ok... but as soon as it climbs to near 3000 rpm the knock becomes obnoxious. Also, what would be the best steps going forward? Repair (cost)? Part it out? Source a replacement engine? Thanks for the help

https://youtu.be/8GKFfVQcfYA

Big end bearings...You may be lucky and it's just damaged the big end bearings, strip and replace the bearings. But every time you start it now the damage will migrate!

There’s a trx Trackbike that was a project that went nowhere the last few yrs up for sale on Facebook for $1700.
There’s your motor plus plenty of spares to sell off and your brother can re coup some of his losses.

Motor swap over should only take a couple of hrs...