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1984 Grady with Mercruiser 470 170hp. Opinions please.

with a Mercruiser 470 4cyl. 170hp motor. Any opinions on this power plant?
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Ayuh,.... Mercruiser's red-headed bastard step-child, they've abandoned,..??

Ya, find another boat...
 
470 4cyl. 170hp motor
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When it is in tip/top condition the power to weight ratio of this engine is nearly unmatched. The problems with it are mountainous but can be overcome if you have unlimited cash flow. Major parts, esp. manifolds, are nearly extinct and not cheap if you can find them. If you must have this boat because it is in excellent condition and the engine was recently remanufactured and has a new carb and upgraded alternator then buy it for a few dollars, sell the working engine and repower w/a V-6 from a salvaged boat. But, only if you can do the work yourself. It would be a great project boat for someone that has cash to burn, likes pain, frustration, aggravation and wants to increase their vocabulary of four letter words. In other words; RUN!;):D:rolleyes:
 
Well be careful what you ask for! Some pretty strong opinions by everybody. None of them very good. It's too bad because the boat is in very nice condition and well maintained.
 
I like Guy's idea of dumping the 4 banger and swapping in a good solid 4.3 V-6; as long as the doghouse has the room for it.

Rod
 
It`s really too bad that this motor had so many nagging problems and parts are so expensive and hard to find. I sold Silverline boats back in the early 80`s and we had a new 16 ft with the 470 in it. Swapped the prop for an ss and clocked that boat with a radar gun at 57 mph.Thing would literally jump out of the water and be on plane on not much more than the length of the boat Had the same motor in a 22 ft Sangster fisherman model which was a reasonably heavy boat with a flush back deck. Stock aluminum prop and it would do a solid 36 mph . A 19 ft Silverline with a 188 hp v8 would barely keep up to it.
 
Sea test the boat and check gauges during operation. Test the power trim/tilt on the water.

It's too bad because the boat is in very nice condition and well maintained.
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Well then buy it. You'll enjoy it while it works. Come back here when the engine is having issues. Before handing any cash to the buyer get the boat inspected by a professional surveyor. Specific areas to check includes all gauges, switches, dash and cabin lights, bow and anchor lights, bilge pump motor and blower motor, engine compression and cooling system integrity with heat exchanger inspection and cooling system pressure test including the cap pressure and water hose condition and charging system operation.

Check the trailer lights, tires for dryrot, wheels for damage and bearings for proper lubrication. Inspect the boat deck, stringers and transom for moisture content w/a gauge and visible/hidden rot. Waterlogged and rotted wood must be replaced--repair cost is expensive. Inspect all storage bins for mold/mildew. Carefully inspect all of the outdrive bellows and water hose for checking/cracks a for dryrot--they need to be replaced for about $1,200--if the aforementioned conditions are found.

Pull the outdrive cap off and inspect the gears for missing teeth and overheating--oil w/smell burnt and the gears will be dark blue/black/brown or scortched. Very expensive repair cost. If found it's a good sign of overheating from low oil level at one time. Remove the oil drain screw and catch an ounce of OD oil for inspection. Oil should not be milky--that's water intrusion--$750 reseal. Have the OD removed and the drive shaft and U-joints inspected and lubed. With the OD off inspect the gimbal bearing for smooth rollout. If it has a rough feel--$250 fix. Finally, wipe the grease out of the engine coupler splines and check for square cut splines. If the spines edges are rounded and not square the coupler grease has been neglected--it will fail and slip one day sooner or later--$750 repair. Use an engine alignment tool to check/reset OD to engine alignment.

Things to remember:

1 - Follow the Merc. recommended PM schedule. Before each use check all of the fluid levels and inspect the engine for oil and antifreeze leaks.
2 - Get a packet of limus paper to regularly (Monthly) test the PH level of the antifreeze. Doing it will prolong the life of the cooling system.
3 - When the outboard stator charging system craps out replace it w/a single wire 60 amp integrated marine alternator--a complete kit is available. 4 - Use only a top quality marine starting & not a "Maint. Free" battery to reduce the work load required by the outboard charging system.
5 - Keep battery terminals clean on both ends of the cables. Spray battery terminal protector on each cable end to stop corrosion.
6 - Install a battery charger/tender to the battery. Get a 10 amp (5+5) two output charger. If you only use one battery then double up the two
5 amp output wires on the positive terminal.
7 - When the distributor shaft wears out replace it w/a new Delco self contained model.
8 - When the 3 tube heat exchanger corrodes thru replace it w/a 4 tube heat exchanger.
9 - Consider ordering a replacement manifold/riser now before stock runs out. You can always sell it.

Good luck.
 
...as long as the doghouse has the room for it.
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I bet that the mfgr. installed centerline engine mounting blocks to acommodate straight block engines. Side blocks attached to the stringers will need to be glassed into place. Not a major job though. I would dump the doghouse and build a sundeck w/removable tilt bench with hinged seat top for underseat access to dry storage and cooler. Engine servicability also improves if the seat/deck combo is built right.
 
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