Fiat Uno Speed ​​Failure

Good I have a fiat one engine 1.3 carburado that does not run more than 110kmh previously reached 150kmh did the following

maintenance
by changing the 92-105 naphtha gillet original to 105-110
new ignition coil, spark plug cables, spark plug It does not rise temperature but it does not go from 110kmh I need them to help me with that problem

What fuel do you make? Did you change the fuel filter?
What type of transmission do you have? Will you not spend the clutch album?

In Venezuela there are only two types of fuel 91 low and 95 Super I put 95
new gasoline filter
manual transmission 5 completely new clutch speed
(press and necklace disc)

Do you verify that with the thorough accelerator pedal, is the butterfly completely open?

Good friends thank you very much for your opinions,
I already check that
a question the distributor counterweights would have something to do with that in low speed