Re: 165 hp merc 4 cyl questions
Most here would say flat out NO but here is my opinion, for what is worth: That motor is going to be 20+ years old, and you are probably on a budget if you are considering a boat that old, so if you are not mechanically inclined and would feel comfortable doing major engine work like removing the head or replacing the water pump cam seals yourself, don't do it. If still reading, there are some things that you MUST do: Ask for all of the repair records, and see what has been done to the motor. You need to see the motor run and be prepared to spend some time (1 1/2 hour or so) to check it out. Stop over to Autozone and pick up a tach/dwell meter, compression tester and cooling system pressure tester (they will let you use them free). You will need full access to the engine so have them pull the box from around it. Do the cooling test first, if it passes, hook up the tach, and with the engine running about 1000 rpm pull the plug wires from the distributor one at a time and note the rpm loss, it should be the same for all cylinders, if not be suspicious. with it running check the weep hole on the front of the circulating pump (lower starboard side of pump) for any sign of leakage, If leaking you need new cam seals, a pain , but you can do it if there is enough room to pull the harmonic balancer off the engine, otherwise big money to fix. If everything is OK, with the engine warm, do a compression check. Pay special attention to cyls #3 & 4 if either one (especially 4) is even 10# lower than the rest it will probably need either a head gasket or valve job. Lastly make sure that the battery is charging properly. Have them fix the tach before you buy it. So there you have it, it is up to you now. Oh and if you decide to look for a 4.3 V6 get it in writing that if the block is (or has been) cracked, you get your money back. Good luck. BTW I do like mine.
