How-To Spring Commission A Marine Engine
(continued - part 2)
Before you install the propeller, inspect its blades for nicks and dings.
Otherwise the wheel will vibrate and cause premature wear to shafts and
bearings. Straighten dings with a rawhide mallet. Minor nicks (smaller than
your thumbnail) can be filed smooth. Remove as little metal as possible to
prevent unbalancing the wheel. Examine the propeller's shock absorber
bushing for cracks or otherwise obvious damage.
Coat the propeller shaft with corrosion fighting, marine grade grease, then
re-install the propeller using a new cotter pin. Check water intake and
discharge ports for obstructions.
Examine the sacrifical zincs noting they should be replaced before they've
corroded away to less than half their original size. Regardless of whether
or not an individual zinc needs replacing, remove it and make sure there's
good metal to metal contact between the zinc and its mating surface.
Otherwise it won't work its magic. Before replacing, coat the bolt's threads
with anti-corrosion grease.
Inspect the powerhead for loose, missing or damaged parts. Lay a wrench on
every bolt, including engine mounts and manifold bolts, making sure none
have vibrated loose. Don't forget the steering linkage! Tighten as
necessary, but do not overtighten. On outboards, be sure to check the hold
down bolts that secure the motor to the transom. Tip: An outboard motor's
loose and dangling hood rubber can be glued back in place with weatherstrip
compound.
Last fall during lay-up, you wisely loosened the alternator and water pump
drive belts. Before snugging them up again, first inspect for cracks,
checkering or frayed edges. Replace as necessary. Correct tension allows for
about 1/4 to 3/8 inch play measured midway between the pulleys.
Similarly, visually inspect cooling system hoses. Checkered or cracked
surfaces indicate replacement is necessary. Firmly grab each hose. Any that
have lost resiliency and become hard and brittle, or are have bulged require
replacement. Also check the hose clamps replacing any that have corroded or
been otherwise damaged. Lay a screw driver on each one making sure vibration
hasn't loosened them.
Last fall you mothballed the motor by fogging its cylinders with a sticky,
preservative oil that resists sliding off the cylinder wall's polished
surfaces. Come spring, this oil must be blown out of the combustion
chambers. To do so, remove all of the spark plugs. Throw the throttle lever
wide open. Crank the engine for about a minute, staying clear of the oil
vapor that blows out through the sparkplug holes.
Hint: Before cranking the engine, open the fuel line valve so that cranking
the engine not only clears the fogging oil, but also pre-lubricates bearings
and fills the carburetor float bowl.
- continued -