Chesapeake - hang on . . . you need a second opinion. His feedback sounds very suspicious . . . and incomplete.
1. Did the mechanic tell you there was evidence of a coolant leak? or leak in cooling system? If there is a leak in the cooling system (where is the leak?)
If he actually said that there was a coolant leak . . . take the engine back to him and ask him to show you where to add coolant to your two stroke outboard!! (there's no coolant in any outboard)
Also where was the exhaust leak?
2. What were the exact compression numbers? Those old 235's are low compression engines if I recall correctly . . . around 90PSI was normal.
3. Ignition Wiring is no big deal to replace. You don't need to buy any special omc wiring
(unless you need a harness). Just got through rewiring the ignition on my old merc 225 . . . you can buy a few spools of appropiate gauge wire and terminal ends and do this yourself.
Trigger and stator wires cannot be replaced, but they can be trimmed back if nesscessary and you can crimp on new wire.
4. Throttle cables could use replacing . . . . around $30 + shipping will buy you 2 new 17or 18ft cables.
For example:
http://cgi.ebay.com/ebaymotors/ws/eB...category=31283
5. The most troubling feedback is the "bad" noise from cylinder number 5. Did you hear the noise? Did he offer any insight into what might be causing the noise?