New Boat Owner... need advice

I just purchased my first boat. 1998 Cobalt 232, with Mercruiser 7.4L, Bravo one Outdrive, 21P prop...

I am a decent auto/motorcycle mechanic but I am new to the boating world. I checked the engine oil and it looks full and really clean (not black) I changed the Outdrive oil and it looked clean with no water.

Here are my questions.
1. Was told to replace plastic freeze plugs with brass, is this a good idea?
2. My speedo is not working, Did some research... pulled the fitting off the middle of the outdrive and the hole in the bottom of the outdrive is clear, where is the next break in the line where I can check for blockage? Do I need to pull the gauge?
3. When I am WOT cruising about 4K rpm and I cut the throttle the boat turns hard to starboard, is this normal?
4. How do I check the water pump impeller?
5. Any advice on things to check? Common problems?

Re: New Boat Owner... need advice

1: I've never seen plastic freeze plugs in an engine. But if it ain't broke I wouldn't mess with it...
2: as long as the pitot hole in the outdrive is clear and everything is in tact down there I would check the connections at the guage.
3: is the weight in your boat distributed evenly? I don't think any boat should turn hard just because you cut the throttle. IDE start checking your steering system for anything being loose.
4: I have an alpha but bravo should be about the same. Drain drive oil, put boat in gear, remove 4 bolts on lower part of out drive, slide lower unit down and off, impeller is in there. May be some more bolts to remove for you but that's the basic gist.
5: since you just bought it I would definetly not trust swine else's maintenance. Change the oil, drive lube, impeller, plugs, distributed, rotor, maybe wires, and definetly check the exhaust manifold and exhaust riser for any external rust. If there is any external rust or the riser runs too hot to the touch pull them and inspect and replace gaskets. Checking those two items are very important especially if you operate the boat in salt. They require replacement 3-5 years and should be inspected annually if 1 year or older. If they corrode through as they will after a period of time you could hydrolocked and toast your whole motor.
6: got to the first sticky thread in this forum. It has lots of good maintenance related stufff like what you just asked. And there is a link for online versions of the merc factory service manuals. Look at that or buy one if you plan on working on your boat yourself.

Welcome to the boating world!

Re: New Boat Owner... need advice

1. I think you mean plastic drain plugs --- some people do most don’t --- they are prone to breakage. No big deal if they do just heat the tip of a screwdriver and jam it into to plastic left in the hole, they usually will screw right out. I do recommend that you buy extra plugs and the o-rings that fit them if you plan on doing your own service.
2. Try blowing about 20 psi of air while somebody watches the speedo. Should see about 20-30 mph on the gauge. There is one more connection just inside the boat where the hose come thru.
3. Check the steering components but it could be the transom cut out is a little off center or the hull has a slight warp from sitting on a misadjusted trailer or lift. A little of that is normal.
4. On a Bravo the sea water pump is inside the boat it will be driven by the belts at the front of the engine. Labor costs more than the parts so it is usually replaced rather than inspected. Recommend every 1-3 years depending how and where you boat.
5. Exhaust manifolds, risers and elbows along with u-joint bellows are two of the things that proactive maintenance is way cheaper than letting them go bad.
6. +1 on factory manuals ---- stay away from the aftermarket ones.

Re: New Boat Owner... need advice

Anybody buying a used boat needs to do the following immediately:

1. Clean and inspect the trailer bearings. Repack with grease for peace of mind.
2. Have a dealership pressure test your lower unit. It tells if there are any leaks. Many older boats need seals.
3. Change the water pump whether it needs it or not. They need changing ever 3 years most often.
4. Replace the spark plugs.
5. If carb equipped, check the throats of the carb(s) after the warm engine is cut off--looking for drip, drip, drip (indicating sticky needle valves.)
6. Inspect the bellows closely for weathering and cracks. (I had a boat sink once because of a bad bellows.)
6. I've always had aftermarket repair manuals, and they have done well for my use (minor repairs.)