Hi,
I have recently bought 2004 japan import suzuki kei 660CC EFI. Everything was fine but acceleration is dead slow. First 3 gears don't make much impact on speed only 4th and fifth gears work little better and after 5 minutes of constant acceleration suv reached at 90KM somehow.
Please any advice as this is my first car and I have no experience. Previous owner told me clearly that engine is weak and I can swap assembly in somewhere between 20 to 25K as spare parts are cheap for this car but before going to mechanic I hope to get some guide line from experts here. Should I go for engine swap or overhauling of engine because suddenly I am out of budget 
Waiting for your expert advice and opinions. And please if someone else has own this car I would love to see review.
Thanks