I have often said that these lower units on the 60 degree loopers are NOT robust.----See many with gearcases coming to a " dynamic halt " and scrapped.
These are matched parts.----Pinion gear is not available separately.----And the new pinion gear must be set up with special tool to determine correct shimming !!-----With shift pushed all the way down it should pull out easily.
Many times a motor that is in poor condition is put up for sale.----Post your actual compression test results here.----Flywheel key may be sheared.----Trouble shooting an outboard takes just minutes.----If you answer questions you may be able to avoid an expensive trip to a shop.
Need more information to help you.----Is it original with one piece driveshaft ?----Any water in it that might have frozen.----Ever had a seal kit installed ?----Pressure tested the gearcase?-------Here I would take it apart and look at condition of driveshaft seals.----Shift rod o-ring.----And...
All flywheels are installed with locking tapers.----They need the correct puller and technique to get them off.----Hurry to your local boat shop and have it pulled.
Not sure why someone would say that is the rectifier !----Most shops take that stabilizer off and throw it away.-----So try this simple test.----Open low speed mixture screws 1/8th turn at a time as that often makes bogging go away.----And are you pushing the key in and holding it in for cold...