Bent connecting rod! What do i need to know before swapping a bottom end?

[Fawkes]

Hello Everyone!

I have an 85 ATC250es that i picked up at an auction about a month ago. The engine was locked up solid but i got it to break loose and she turned out to be a decent runner. It smoked and used oil so yesterday i pulled the jug to do a top end and found out the connecting rod is bent. Im guessing it got hydrolocked before being parked years ago, or bent when i broke it free (unlikely because it didnt take much). I dont want to give up on this project but im off the deep end now. I think my best bet right now is to buy a complete bottom end. What scares me, is i really dont want to split the case and have to go through everything, and i found out about the issue where if you remove the output shaft you have to split the case to put it back together. So my question is, are there any other parts that require the case to be split to reinstall them? Im going to attach a couple pictures for the type of deal i was looking at getting. Please let me know if im going down the wrong path here.

[legacy51]

I think you would be better off doing a new rod. Buying a bottom end off ebay isn't a guarantee. If you split the cases, have a shop put a new rod on the crank, install some fresh crank bearings, and do new bottom end seals, you know exactly what you have. Splitting the cases isn't as bad as you might think. I haven't split a big red bottom end, but Honda's usually have clips to hold the transmission onto the main and countershafts and that makes them nice and easy.

[ATC King]

Hello Everyone!

What scares me, is i really dont want to split the case and have to go through everything...

That's pretty much the case with anything you'll buy used, unless someone has already fully dissembled and inspected it. These things are old and unless it's been a one owner, who kept well organized and complete maintenance and repair records, it's all postulation.

At this point, if you've got good cases with no damage and repairs and the internal spinning bits aren't rusted or pitted, you're already ahead of the game.