HELP..!! Cleaning fuel tank without removing it

[Mario]

Hello

I have this zed I am trying to put back on the road after being in storage for many years.

The fuel pump was seized and then I removed it there's this tar like substance on the bottom of the fuel tank.

Is there any way or product I can use to try clean as much as possible?

I can reach with my hand inside the fuel pump area to clean but this is tank has another lobe/hump behind the passenger seat right? How do I reach there? How clean does the tank need to be?

I am not sure also if there are other books and crannies I should be able to reach from the pump hole. I can also fill the tank with something let it sit so it dissolves and drain as much as posible right?

Thanks guys

 

[Delk]

Never had to clean a plastic tank before. I can only think of putting some sacrificial fuel in and sloshing that around a bit before removing it.