Engine identification

The throttle cable is like new and works smoothly. It looks like the the mechanical link age is working. The engine appears to stay at max speed. I do not hear the engine speed up when I engage the mower. I used to always hear the govenor increase when the mower was engaged

Mower starts on first pull then dies when choke returns to normal. Mower has only been used twice

I have a 98 civic lx with a manual and tonight I was driving and the car just turn off on me while driving at 70km/h in 4th gear. Then tried boosting the battery but every time I tried to start it the engine didn't even turn at all. Some possiblilities I thought of was that the battery is...

Mower was running fine, started making a noise inside engine, lost power, noise returned, and engine died. No longer will start, just spins. Is the engine trashed or possibly fixable?

Need help please identifying the engine we are working on. It's a 1991 honda Civic 3 door 1500 car, but we have a suspicion the engine has been switched out. (We just bought it.) The engine number is A18150570. Do you know how to find out what year this engine is?