R 80 GS power problem

[Samy]

Hi friends,

My R 80 GS Basic (1997) which I am second owner is upgraded by former owner from 800 cc to 1000 cc by changing cylinder heads only.

Nothing has been changed other than cylinder heads. Carbureateur and the spatk plugs stayed same as original.

The result is: on the highway I reach to 140 km/h difficultly and after reaching normal workin temperature. At the beginningi when engine is cold I can't reach over 110 - 120 ks/h easliy. When climbing a hill, I can't get more speed than 100km/h.

I think this is not normal.

I am not complaining and not looking for more speed but when I need speed for overtaking or to reach somewehere or in the highway, it bothers me.

I really don't know what is the normal speed of R 80 GSs with 800 cubic engine? Can they reach a top speed of 180 km/h and ride at speeds 150/160 km/h normally without any problem?

* Should I change carbs for better power (I don't want it to spend more gas, which it is already spend a lot)
* Should I go back to 800 CC (why spending extra money to go back?)

Any advice and experience pls.

Wishing the best,

Sami