Cash out Refi question - need your input!

[Steve S.]

One of My rentals I acquired for $100,000. I put $25,000 down and have been laying on a 30 year noTe For several years

Interest rate - 3.75%

Remaining balance $70,000

Property value is $200,000

Assuming I could get an 80/20 loan, that should be a mortgage of about &160,000 putting roughly $90,000 in my pocket

I have anothe investment I believe will generate 10% returns. 

1) what interest rate do you think I could donthis at?

2) is my general Math above correct?

3) why would this be a bad idea?