250-500cc How long are the bottom ends good for?

I am finally putting a new piston in my wr300 at 2500 ish miles from stock piston. My mechanic friend mentioned if I ever get to the point when needing bottom end work I should consider replacing the bike as that would cost serious money. Right now its an amazing bike. Dialed in completely and does everything that all the new bikes do. BUT- its hardly worth anything in value. So my question is at what point would I need to worry about crank and or bottom end issues?

Why would you say it's hardly worth anything? It depends on so many thing...

As to bottom end...it all depends man...all depends I was quoted $500 for the labor + parts

See this thread: http://www.cafehusky.com/threads/bottom-end-shelf-life.29841/ Ironically, in that thread you post and answer to some other guy asking the same question.

"Needing bottom end work" is really vague. Eventually, you'll need to replace the bottom end bearings. That's a bigger job than a top end, but it's not a big deal and not really that expensive. I'd hardly trash a bike because of that. Further down the road, you might need to replace a crank, but I think a properly cared for 300 will be so otherwise worn out by that point that it won't matter much anyway.

You're doing your first top end on your 2009 at 2500 miles. In another 4-5 years you can do the top end again (and maybe some bearings), and then again 4-5 years after that. At that point, it'll be 2022, and the bike might need bottom end work.

Also: http://www.thumpertalk.com/topic/797203-how-many-hours-do-you-get-on-a-bottom-end/

I replace the bottom main bearings and seals when I split the cases. I split the cases if the piston/cylinder came apart...or I want to change transmissions.

Replacing the main bearings is a long and delicate process, but it's not difficult, it will take a good 4-6 hours depending on if you have all the right tools and if you know what you're doing.

Replacing the big end bearing on the rod, I take the crank into a go cart shop, and they handle that work in no time. Last one I did that with was a KTM and it needed a bearing race pressed on as well. It was $40 for all the labor. But, unlike the KTMs the Huskies don't have a bearing race to press onto the crank, so the bearings are easy.

Oh ok. I have to remind myself my mechanic friend is extremly anal too-lol. He just was lecturing me. Add to that I know a guy who had his ktm 300 cases split and when all was said and done he spent around $800. So was being a little paranoid

Even if it did cost $800, wouldn't that be money well spent to guarantee a happy bottom end for another 5-10 years? I don't see an $800 job relegating a bike to the scrap heap.

Guy in Belfair does it competently for $150-200. No big deal. Don't go looking for reasons to buy a new Beta.

Actually to clarify- I wouldn't get rid of the bike. Just relegate it to "backup" bike. But I like being cheap and ride the piss out if it next couple years.

Your bottom end should outlast several pistons so ride on !