Marine FAQ's

 

We know that time in your boat is valuable. Every boat serviced at Dandy Auto Marine is inspected by our team of factory trained technicians.  We continually invest in ongoing training to ensure our technicians have the knowledge and up-to-date skills demanded by today's technology.

 

Recommended Service Inspection Summary

Each boat winterized by Dandy Auto Marine receives a very thorough multiple point "bow to stern" inspection summary. The technicians test and evaluate the operating systems of your boat to identify and confirm any areas of potential failure at spring run-up or after spring launch.

 

Manufacturer’s Scheduled and Periodic Services                     

It has been determined that a marine engine works 4.6 times harder than an automotive engine. This has been calculated through fuel consumption versus time, establishing how much actual “work” a given engine performs. This is of course is magnified above this level, when ballast and additional weight are introduced into the boat.

 

It is said that in the typically powered 20’ pleasure boat, that the work the engine performs equivalent to a truck pulling an 8000 lb. trailer its whole life. Not to mention many boats spend the majority of their time either at either idling speed or at or close to wide open throttle.

 The "secret" to prolonging the life of a four stroke marine engine is common-sense simple: 1)Change the crankcase oil regularly,

2) Keep the ignition system in tune

3) Monitor the cooling system and impeller condition.

If you follow these three simple rules, your stern drive or inboard gas engine will grow old gracefully. On the other hand, should you neglect to maintain these systems the odds are good that your engine's health will suffer, and its life span will consequently be dramatically shortened.

So exactly how often should you change oil and tune the engine? At a minimum, always change the oil during winterization. The rule-of-thumb is: Never log more than 40 hours without an oil change. Engine manufacturers all recommend specific tune-up intervals and oil-change intervals (as well as what type of oil to use). Make sure not to exceed these intervals.

 

Engine Oil

The "health" of an inboard's lubricant is critical, because marine power plants run hotter than their automotive counterparts. They also work much harder. They're either idling dockside or under constant load. Offshore, there are no hills to coast down. Even when trolling or transiting a no-wake zone, a marine engine has its nose to the grindstone.

Another lubrication problem relates to winterization. As gasoline burns, it deposits acid residue in crankcase oil. Acid content isn't really a problem when oil is changed on schedule. But if old oil remains in the engine over the winter months, the acid etches the bearings, piston skirts, crankshaft journals, and other critical wear surfaces.

Oil has another interesting property and that is its ability to migrate away from bearing surfaces, if left static for a period of time. The issue is that when the oil migrates it leaves behind the carbon and impurities it was previously suspending. When the engine is first started at spring run-up the bearings and mating surfaces are spinning on grit before the arrival of the oil from the oil pump. Simply changing the oil during winterization prevents this premature wear.

Unfortunately, most boat owners are somewhat lax when it comes to oil changes. If the family car were neglected the way the typical family boat usually is, major repair bills would begin piling up around 50,000 to 75,000 miles. But, if pampered with frequent oil changes and periodic tune-ups, that same car engine could log up to 300,000 miles without an overhaul.

Manufacturer Recommended Service

Service: Engine Oil and Filter change

Manufacturer: Indmar, MerCruiser and Volvo Penta

Link: http://www.indmar.com/About/ContactIndmar/Manual_2003_Presentweb.pdf

http://www.marineenginedigest.com/diy/8simplerules.htm 

Description: The "health" of a marine engines lubricant is critical, because marine power plants run hotter than their automotive counterparts. They also work much harder. They're either idling dockside or under constant load. Offshore, there are no hills to coast down. Even when trolling or transiting a no-wake zone, a marine engine has its nose to the veritable grindstone.

Ambient air temperature in marine engine compartments is much higher than the temperature of the air surrounding an automotive engine. In fact, marine engines are like mini-oil refineries, cooking off a lubricant's lighter molecules and leaving behind the heavier molecules. As the engine logs hours, its oil transforms into a sticky varnish--which is why oil changes are so vital to the life expectancy of the engine.

The two images below show an oil cap removed from an engine which has benefited from regular oil changes and an oil cap removed from an engine which has not had its oil changed at reasonable intervals, compounded by being stored with dirty oil in the engine. Note the thick sludge

 

 

Engine Tune-up

In addition to changing oil regularly and during winterization, tune-ups are another vital element in extending engine life. Marine engines are operating under much higher throttle openings and much higher RPM ranges than automotive applications. A weak ignition spark does a poor job "lighting the fire." As a result, not all of the fuel/air mixture burns. Not only do performance and fuel economy suffer, but unburned, abrasive hydrocarbons also deposit themselves on pistons and combustion chambers.

In extreme cases, unburned gasoline washes lubricant off cylinder walls, causing excess heat and friction to score them. And when gasoline gets into the crankcase sump, it dilutes the oil, reducing lubrication even further. Rings begin to stick, which reduces engine compression pressure. If the oil rings are damaged, the engine becomes an oil-burner.

Ignition components also experience accelerated corrosion and aging due to extended lay-up periods.

Manufacturer Recommended Service

Service:

 Engine Tune-up

Manufacture:

 Indmar, MerCruiser and Volvo Penta

Links:

http://www.marineenginedigest.com/diy/8simplerules.htm

http://www.boated.com/topic.asp?TOPIC_ID=111643

http://www.indmar.com/About/ContactIndmar/Manual_2003_Presentweb.pdf

http://www.mercurymarine.com/_media/pdfs/serviceandwarranty/sterndrive-models/Non-EC/90-899883179-Maint.pdf

http://www.volvo.com/volvopenta/na/en-us/marine_leisure_engines/parts_service/publication_search/publication_search.htm

Description: 

A properly tuned engine is key to performance, fuel economy, reliability and engine life.Tune-ups are a vital element in extending engine life. A weak ignition spark does a poor job "lighting the fire." As a result, not all of the fuel/air mixture burns. Not only do performance and fuel economy suffer, but unburned, abrasive hydrocarbons also deposit themselves on pistons and combustion chambers. An out of tune engine can also lead to pre-ignition / detonation which can cause severe piston damage.

Ambient air temperature in marine engine compartments is higher than the temperature of the air surrounding an automotive engine. All this heat in addition to the water contained in the bilge,produce an elevated humidity level with rampant corrosion of ignition components. These factors added to the hard work combine to push marine engines to the edge of the envelope.

In extreme cases, unburned gasoline washes lubricant off cylinder walls, causing excess heat and friction to score them. And when gasoline gets into the crankcase sump, dilutes the oil, reducing lubrication even further. Rings begin to stick, which pulls the plug on compression. If the oil rings are damaged, the engine becomes an oil-burner.

Procedure:

Perform cylinder compression test. Remove and replace the following components:

  • Distributor Cap
  • Distributor Rotor
  • High Tension Leads
  • Spark Plugs (analyze plugs for problem signs)
  • Distributor Ignition Module
  • Alternator Drive Belt
  • Fuel Filter(s)

Clean flame arrestor, set choke and idle speed (non fuel injected) and set engine to specifications. Connect to laptop Diacom and check for codes (where applicable).

  /

 

Cooling System

The third rule for engine longevity is to maintain the cooling system. Most sudden engine failures are due to overheating. Almost all overheating conditions experienced with a marine engine are due to lack of maintenance to the Raw Water Impeller. When an engine loses its cool, rings score cylinder walls, mufflers melt, manifolds crack and heads warp.

Manufacturer Recommended Service

Service:

Raw Water Impeller

Manufacture:

 Indmar, MerCruiser and Volvo Penta

Link:

http://www.indmar.com/About/ContactIndmar/Manual_2003_Presentweb.pdf

http://www.mercurymarine.com/serviceandwarranty/mercruiserfaqs/maintenance.php

http://www.mercurymarine.com/_media/pdfs/serviceandwarranty/sterndrive-models/Non-EC/90-899883179-Maint.pdf

Description:

The neoprene rubber raw water impeller draws fresh water into the engines cooling system. A failed impeller will cause over heating, which can lead to many different and costly types of engine damage. At left is a failed impeller. The separated pieces of rubber can circulate into the engine and cause blockages, leading to added over heating problems. Image on right is a new impeller.

Inboard: Remove raw water cover and utilizing an impeller puller, remove impeller from splined pump shaft. Refit new impeller and re-install cover with new gasket. Run engine and check for proper water circulation.

Sterndrive / Outboard: Separate lower unit gear case from outdrive. Remove water pump housing. Replace impeller, base plate and seal. Reassemble housing and re-install gearcase on outdrive. Run engine and check for proper water circulation.

 

  

Gear case

By far the most common failure on stern drives is gear damage. In most cases, the damage could have been prevented if the owner had regularly checked the gear case lube. To do so, crack the bottom drain plug and let the liquid drain out. A few drops are all you need: If you see nothing but lubricant, tighten the screws and get on with your life. But if water seeps out, keep the plug loosened and continue to let the liquid drain out until pure gear oil begins to flow.

If less than an ounce of water came out of the gear case, a seal is leaking, but not seriously. Monitor the situation carefully, checking the gear oil before every outing. If more than an ounce (a shot glass full) came out, stay at the dock and find out why.

This lubricant test is best performed after the stern drive has been idle for at least a couple of hours. That way any water will have settled to the bottom of the gear case. If you don't wait, the water froths up into a milky-white liquid. You can tell water is present, but not how much.

Manufacturer Recommended Service

Service:

Gearcase Reseal / Overhaul

Manufacture:

MerCruiser, Mercury and Volvo Penta

Link:

http://outdriveshop.com/white_in_gearlube.html

Description:

White streaks and milky appearance are an indication that you have water in your gear lube and / or oil seeping from the gearcase. This is a very serious condition which will eventually lead to serious damage.

Water can get into the drive from a bad seal or a bad o'ring. Seals go bad after a few years and need to be replaced. Usually drives are resealed every 5 years, less if you have overheated your engine.

Water can also leak into the drive if the Ujoint Bellows are leaking. The front main seal of the drive is not really designed to hold water out as much as it is to hold oil in. If you develop a water leak into the bellows it can let water into the drive itself.

When water gets in the drive it tends to condensate on the top bearing. That's because drives have an air pocket in the top. The moisture rusts the race and bearing needles. The water also rusts the shaft races and gears. When the drive is then used the rust "pits" the metal surfaces and bits of metal shave off with each revolution. The metal bits add to the process and soon the gears, bearings and shafts fail.

If you find water in the drive... damage may have already happened. Simply changing the drive lube will not fix or stop the damage. Once a bearing, gear or shaft is rusted, it must be replaced.

Removing the top cover from the drive will usually reveal the level of damage. If the top bearing looks PERFECT (no brown water stains, rust, pitting or streaks) you should be OK. If you see brown stains, the hardness of the metal has been ruined. Don't run the drive with a damaged part(s). You might turn an expensive repair into a much more expensive repair.

 

Transom Bellows

The transom bellows, on a sterndrive boat, are flexible accordion type rubber assemblies that allow the turning and tilting required in the outdrive propulsion unit or "drive leg". The three sets of bellows accommodate the through transom passage of the drive shaft, the shift cable and the engine exhaust. Their function is to keep water from entering the boat and drive assemblies.

Overtime due to weathering and movement the bellows deteriorate. A boat that was not leaking in the fall and is not properly inspected prior to winterize, could have the bellows fail shortly after launching in the spring.

 

 

Manufacturer Recommended Service

Service:

Transom Bellows Replacement

Manufacture:

MerCruiser and Volvo

Link:

http://outdriveshop.com/water_leaking_in_transom.html

Description:

The "transom assembly" is actually the Bell (Gimbal) Housing Assembly.
The Gimbal Housing assembly has rubber components (bellows) that can rot and/or rip and leak.
The two rubber components most likely to cause a water leaking into the boat are the Ujoint Bellows and the Shift Cable Bellows.

Replacing the Shift Cable Bellows requires removal of the drive and replacement of the shift cable.

Leaking U-joint bellows will cause severe damage if not tended to immediately. Not to mention the boat possibly sinking.


The two most common symptoms noticed first by customers are water constantly leaking into the boat
and noise coming from the back of the engine/drive area. It's important to note that once these things are noticed, that some damage has already occurred.
The grumbling noise that so many customers hear is from a rusted gimbal bearing. The noise will get worse as the drive is turned to full left and full right.
Sometimes a customer will notice water in the drive lube as well. The front seal of the outdrive is meant to hold OIL in the drive and is NOT meant to hold water out of the drive.

Inspect the Gimbal Housing Assembly:
With the boat out of the water, take a good look at the bellows with the drive placed in different positions.
Look for barnacle growth, rips and deterioration of the rubber. The bellows should be clean and firm
A complete inspection will require the removal of the outdrive.

The rubber bellows should be replaced about every five years or sooner if you suspect a leak.

Gimbal Bearing

The gimbal bearing supports the drive shaft as it exits the transom of the boat through the gimbal assembly and connects to the outdrive. Gimbal bearings become compromised when exposed to water. Water can contact the bearing in two ways, the bellows leak (see previous) or the water level in the bilge becomes high enough (aggravated by bow rise and acceleration) and water flows through the transom plate into the housing.

 

Manufacturer Recommended Service

Service: Gimbal Bearing
Manufacture: MerCruiser and Volvo Penta
Link: http://outdriveshop.com/gimbalbearings.html
Description: A bad gimbal bearing can cause lots of expensive damage. It can destroy your gimbal, drive and/or drive coupler.

You can usually tell that your gimbal bearing is failing by the noise it makes. A bad gimbal bearing will make a "growling" noise when you turn the drive from one side to the other. If you hear a growl when turning to one side, chances are very good that you have a bad gimbal bearing.

The sterndrive unit must be removed to inspect or replace the gimbal bearing.

Gimbal bearings usually fail because of water intrusion into the ujoint bellows. Ripped or rotten ujoint bellows will allow water to leak in and rust the bearing. There must be no water in the bellows. If you have found water in the bellows the source must be found and repaired. Water can also enter the bellows if you get too much water in the bilge. Be aware that it's useless to replace the gimbal bearing if there is still a water leak. The water will simply destroy the new gimbal bearing.Gimbal Bearings fail for a reason.

Simply pumping grease into the zirt fitting on the stb. side of the gimbal will not fix the problem.
Usually the water that has leaked into the bellows is destroying not only the gimbal bearing but the ujoints and sterndrive as well.

This is why immediate action must be taken.
Failure to remove the drive and address the problem could lead to thousands of dollars worth of more damage.

Even if you don't use the boat.... more damage will occur from sitting.
Rust and corrosion will set in and ruin the gimbal, bell housing and drive.

 Dandy Auto Marine Is committed to helping you maintain your marine engine and helping prevent the main causes of engine failures, reduced performance and shortened engine life.

Please contact us at 403-945-1555 for additional information.