As a 25 year old entrepreneur I am contemplating 2 options -1.

Rather than selling them 50% interest in the LLC, I was contemplating selling/transferring a 50% tenancy in common interest to them where my existing LLC would remain a 50% tenant in common owner with their new entity (LLC) which would own the other 50% as a tenant in common.

Again, you have no savings to cope with anything regarding the rental, not to mention anything else that happens in your life, without raiding your 401K and incurring penalties and taxes, which is imperiling to your retirement.Honestly, consider saving at least 6 months of living expenses, plus the needed down payment, before you even begin to contemplate such an upgrade.

I was contemplating building a 100 unit apartment complex on the Oregon coast some years back or should I put up 80 town houses.I did run a COMING SOON  add in the local paper. 

i currently have a 401k loan that i used to purchase 2 fourplexes that i have renovated and increased rent roll by 30%. i have a ton of losses this year and was contemplating defaulting on loan and hope to avoid paying taxes due to losses.

@Graeme WilliamsYou have very valid concerns and shared with the vast majority of those contemplating investing in real estate.

You've contemplated realistic returns?  

I really contemplated my own sanity for a few years!

These would only apply for 2017, though, since it seems that you're contemplating making it a rental from here on out.  

I have contemplated just hammering down my mortgage with principal payments for the next 3 years and my off my loan, but am getting tired of waiting on the sidelines.