Of the Suzuki engines we have had into work they seem fairly reliable. Down side is cost of parts a head gasket for a 3.5hp was £45 I had to price one today
. Plus points over your current engine would be age, and power trim/tilt (so long as you can use it properly
). Also Suzuki apear to be fairly bomb proof!
Tips for buying a used engine:
Go and see it!!
Make sure it runs without any strange noises (powerhead and gearbox)
Starts easily when hot and cold
Check tell tale and bloke temp when running
Check for excessive smoke (If oil injection shouldn't be too much!)
Check general condition of block, transom brackets and leg for excessive corrosion (and anodes will help workout when last serviced) if not before sale.
If possible get a qualified marine engineer to check it over. It may cost you an hours labour labour but thats better than £100's on a knackerd engine!!
Hapy engine hunting