Hi there,
Straight out of the Haynes manual about the MA12.
bore - 71mm
stroke - 78mm
capacity - 1235cc
compression ratio - 9:1
power output 60Bhp @6Krpm
Not sure what you mean about modifying the carb but it is possible to rejet the carb if thats what you mean?
I dont see any reason why you cant add EFI, it would however mean haveing a new inlet manifold made up and adding some sensors and you would need to use some kind of programmable ECU, i did look into the possibility of useing a modified honda pgmfi to do just this, would work out quite expencive when you take into accout rollign road time to set it up , etc. in my oppinion it is the way to go if you plan a turbo conversion though.
i dont know if they make turbo kits in japan or somewhere but in the UK there are pretty much NO aftermarket parts available for the K10 micra's. and it is also worth noteing that the MA12 engines arent known for their strong head gaskets in N/A form so turboeing one without the use of a copper head gasket, which would have to be specially made and would be quite expencive again, would not be reccomended by me.
Not sure about how much the transmition can stand but my mates car that i tuned was when it got on the dyno giving out about 76Bhp as far as my memory goes, this was from a N/A Ma10. so there is atleast slight room for tuneing without haveing to worry too much about the gearbox. his car is still running perfectly a few months after the tuneing was finished.
car weight depends on model / how many doors, etc.
hope this helps,
Owen