Speedometer will only go up to 40mph, and idea how to fix?

Is the speedo needle bent and catching on the new white face stickers? If it worked ok before that's all I can think of. Their pretty fragile so you may have bent it a little when installing the stickers. You can bench test it with a reversing drill that way your not having to install it to test it. No idea why the speedo cables too short unless someone replaced it and put the wrong one on the car. Mines plenty long.