Well, here is an interesting problem I came across concerning the fuel tank mounting on my 2520. It seems the front mounting brackets are a little sub-standard. What happens is they flex along with the plastic tabs of the tank. When this happens the tank will shift forward enough to cause alignment problems with the fill cap and the relief hole in the hood. Once this happens, there could be enough missalignment to prevent the hood from opening. Or at the very least difficulty in opening the hood.
My first attempt at the solution was to add washers between the bracket and tank to get it back into position. This was only temorary as the problem re-occured. In my next attempt I removed the brackets and re-bent the angle. Currently this is working. Should this fail I will either modify the bracket to make it stronger or just re-design and make new ones. I am hoping that I do not have to do that. The one picture shows the bracket and where I bent it. The bend was made such that the angle was increased from 90 degrees. You have to adjust it to push on the tank to keep the front end of it up in the air.