Engine Rpm Is High After Engine Replacement...!!!

[Rox]

I'm driving a Pulsar (FN15) and recently I had to replace my engine due bad condition inside the engine block. I think an engine overheating has been occurred before I bought it. :-( Anyway, I had no option as repairing the existing engine seems to be costly than this solution.

Anyway I replaced only the engine block with a new one and kept ECU/Manifold, Auto Gear Box and all other accessories unchanged. Now engine runs smoothly compared to before but the only problem is that engine RPM seems to be higher than before at gear shifting. when the engine is in idle, there seems to be no difference. But I feel that I have to accelerate more than before to change gears. The first gear shifts around 20 kmph and the second at 40 kmph. As I am driving mostly in Colombo, I'm running around 40 kmph normally and this tends the gears to be shifted very often. The condition is worse in a road with meny bends :-) Also this leads to more fuel consumption I suggest.

One other thing I noticed is that gear shifting can be felt clearly with the difference in speed now compared to before. Anyway, I did not changed the gear box and the engine is surely a same model.

So please help me with this to figure out what have happened. Why is the RPM's are higher? Why are gear shifting can be felt? Is this normal? How will this affect my fuel consumption? and specially, How can I get rid of this issue? Is there any adjustment in the Auto Gear Box that me have been changed while in the repair?

What is the proper way of changing the Engine Number in the Registration Book to the new one? Will RMV put a remark, that I have changed the engine?

[Rox]

Anyone don't have an idea??? :-O

Pls try to help me with this...!!!

[MeanGreenZ28]

I would've said check all the vacuum lines and see if there is a leak, but that would also show itself when your at idle too.