At times it could be a bit tricky to understand the right time to seek investment. The necessity of fund could be understood only by you, not anyone external to the business. If you feel you have tried and tested the limits of bootstrapping, then funding could be an option.
However, do ensure that you've done product/service validation before seeking investment. An investor may invest in your team, but sans validation of product/service you can end up in more turbulent water.
Secondly, too much money could be dangerous either. Necessity is the mother of all inventions. Too much money could help you do more of same thing, but you may not be able to brainstorm the better ways of doing much better things.
Limited capital could also be helpful in building small and iterating fast. You know, Titanic never returned. But small lifeboats do return. Fail small, Fail early, Fail fast is the mantra to succeed.
So, the right stage and time to get funded is when you have tested your limits to bootstrap, and after you have validated your critical process and product.
In my more than a decade experience working with startups and entrepreneurs, I have helped plethora of them with "Hand-Holding" and investment planning. Try to bootstrap in a right way. Feel free to reach out for any further information that you may need. I am just a clarity away. All the best!!