Pulling up decking on a 170

[Gipper]

How do you take up the decking on a 170.  I need to check the fuel tank.

[RickK]

That's a loaded question  :)
What is the end result you want?  
1. An access just to the tank? Do you want to use a prefab cover that can be opened anytime in future?  Where is your tank exactly?
2. An entire new deck? This will be a major undertaking, not that you are not capable, just be prepared to do more work than you initially think.  The nice thing(s) about this option is now that you have the entire floor opened up, you can make any mods you'd like to have in the finished product.
I've only done the second approach - my tank is above the floor under the console.

[Gipper]

Is the deck lost if I take it up?

[JimCt]

Do you suspect the tank is leaking?  If you are getting whiffs of gas it might be that the hose connecting the fill plate to the tank is weeping.  Might also be the tube going to the fuel vent.  Don't know if these are serviceable on your boat, but if they are they are worth checking out before cutting the deck.

[RickK]

Is the deck lost if I take it up?

I know my deck was useless after the takeup.  If you happen to cut between the stringers you may be able to reuse it.