Refinance my condo to pull $ out for investing OR sit tight?

Hi everyone,

I've yet to dive in.  Just moved out of condo & am renting it out.  Want to refi that condo to invest in multifamily.  I have $100,000 left on my condo loan and am netting $900.  If I refi to pull money out, my new much higher payment will mean that I'm netting nearly nothing.  Is it a good idea to refi to reinvest or just sit tight and enjoy the $900 passive income?  I'm about 5-7 years to retirement from education (not a money making career, but rewarding).

You're advise will be appreciated.  Ready to take a leap.

Lisa