The Dish Network User's Resource
If weather is bad in your area right now, it would account for a lower than normal signal. It's best to wait for good weather to peak your dish.
But, If you are having program quality issues, it will probably help. If your picture looks OK, all it will do is cut down on your rain and snow fade.
You'll need to be able to see a TV or hear the indicator tone while adjusting the dish, an installer should have a signal meter he can hook directly to the dish for peaking.
Alan Dana adds:
I agree with all of the above, but want to add that a 61% reading is extremely poor if the sky is clear. I would not be happy with this at all. I had only 78% for several months and did suffer with somewhat frequent loss of signal during rainstorms. Then I replaced my RG-6 cabling with higher quality stuff and I now get 91% - even with a 156' run from my dish to my receiver. I didn't readjust the dish at all.
So I suspect you either have a 1) Poor reading on a cloudy day. 2) Incorrectly aimed dish. 3) Partially obstructed dish. or 4) Poor cabling.
Low signal strength linked to EPG and switch problems.
It has been stated by some that you will get more reliable switch and EPG operation if your signal strength is in the 70s or above.