I have had three outboards of various vintages and makes.
My first a Suziki 15HP two stroke 1988 vintage
Always started first go cold.
Was a bugger to start hot, often I just had to sit around for 1/2 hour and wait for it to cool down.
Next was my Evinrude 40HP two stroke. 1982 vintage
Would not idle from the day I purchased it,
But after the head gasket was replaced it performed faultlessly for the next 5 years, always started first kick and never missed a beat.
The only thing I had to fix, other than the head gasket was the trim & tilt cylinder that just died of old age. Replaced the seals with the kit ($65.00) and never a problem again. By the way, the t&t didnt fail, it was just leaking.
My new boat had a Mercury EFI 90 four stroke NEW
Brilliant, as it should be, the only 2 problems I have had is that it wouldnt start in cold weather (the dealer put in a battery that was a truck battery and only half the required CCA,
And the fact that the rubber grommet that the wires and controls go through into the motor keeps coming out.
Both the boat dealer and the Mercury reps ahe blamed each other, so I cant get it fixed.
This is a known problem with these motors, checking the web it has ben a chronic issue in the US for years.
Other than that, this is a fantastic motor.
At idle the noisiest thing is the tell tale dribbling into the water