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Care of Your 2-Stroke Outboard

 *Be advised that the break in procedures listed here are for a carburated or traditional EFI engine.  They do no apply to the new high pressure fuel injected technologies such as Optimax or Ficht.

Ok, you have just purchased a brand new (or maybe it's brand new to you) 2 cycle outboard.  How do we determine how to break in and maintain that very significant investment.  The following article will provide some general guidelines on the care and maintenance of your new or almost new baby.  Remember that these are guidelines and that this article are not meant to replace or supercede the manufacturer's owners manual tech bulletins...yadda...yadda...yadda.

Break In:
This section is applicable to new motors or motors with newly rebuilt powerheads.  I have always told customers that the way you treat your motor in the first ten hours is how it will treat you for the first 10 years.  That means if you intend to keep it for any length of time, you'd better break it in right to assure maximum horsepower and reliability.  The first step is to understand that while modern manufacturing techniques mean that today's outboards are built to extremely tight tolerances, there is some "wearing in" that takes place.  As your rings are seating properly in your cylinder there is more friction related heat that is generated. 
To counteract this, you must take two preventative measures
First, during your break in (generally considered the first 20 hours or 40 gallons of gas), you need to provide for extra lubrication.  Generally 25 to 1 at wide open throttle.  To do this you need to add additional oil to the fuel supply.  On a non oil injected engine this means running two pints of 2 cycle oil to every six gallons of gas.  On an oil injected engine this means adding one pint of oil to every six gallons of gas.  During this period of time I like to avoid using high detergent gasoline or running products like Ring Free. 

The other precaution is to limit and vary your rpms.  My general rule of thumb is not to exceed 85% of max rpm during the first 10 hours.  Also, don't run your boat at a constant rpm for more than a couple of minutes.  After break in you should also change your lower unit grease in a new engine since the gears in the foot have worn in and this usually results in some metal particles in your gear lube.

Enemies of Your Investment:
The two major enemies of a 2 cycle motor's powerhead are heat and carbon.  Heat causes excessive and premature wear and carbon deposits cause a host of nasty little problems.  They include (but are not limited to) stuck rings, ring "jacking" and piston detonation.  If you take regular preventative steps to counter your engine's powerhead "enemies" you will easily double the life of your motor.  The modern 2 cycle outboard will last a very long time (comparatively speaking) with no maintenance.  With proper maintenance an outboard can reasonably be expected to appear in your will (saltwater not withstanding).  Ok, these are the enemies....how do you overcome them?

Decarbonizing your motor breaks down existing carbon deposits in your motor.  There are two ways of doing this. 
First you can use a fuel additive like Yamaha's Ring Free in "shock treat" quantities.  This requires dumping a large amount (read the bottle) of this deposit remover/preventer into a specified amount of fuel.

This is generally the only way to decarb an EFI motor since you don't have access to the throttle bodies.  It is the most expensive way to do it but when weighed against the cost of a rebuild it's a bargain...trust me.

The other way to decarb is to gain access to your carbs and introduce a cleaner like Mercury Marine's Power Tune.  First make sure that you have a water source for your engine.  Then remove the cowl and remove any breather box that covers your carb throats.  Start your water then start your motor.  Raise the fast idle lever until you are idling at about 1200-1400 rpm.  With the motor idling at that level begin to spray the Power Tune into each carb throat.  Don't touch your idle and let the Power Tune bog your motor down but don't let it shut it down.  Move quickly from throat to throat until you have used about half the can. 
Here is a tip.....don't point your prop at anything that you don't want to be black and sooty (i.e. the garage door or the wife's new white car).

After you have put the Power Tune to it, shut the motor down and let it sit for about an hour.  Then take it to the lake and run it wide open for about 3/4 of a mile.  If going to the lake is not an option, restart the motor (with a water source) but don't rev it over 1600 rpms on a hose.  After decarbing, running Ring Free, good gas and a good TCW3 oil will limit deposits on a regular basis.  I like to decarb a motor every year or every
100 hours, whichever comes first.

Water Pump Impellers:
Plainly speaking, the water pump impeller is the most ignored routine maintenance on an  outboard.  No magic here, just have it changed every 200 hours in fresh clear water or every 100 hours in salt/brackish water or water with a high silt content.
One tip here.....if you decide to do it yourself, always verify that your motor is pumping water after the job is complete.

Lower Unit Grease, Prop and Propshaft Maintenance:
Prior to the onset of freezing weather each year you should change your lower unit grease.  It is also a good time to pull your prop and check for fishing line that can tear into your shaft seals.  Grease the shaft before replacing your prop (especially in saltwater applications).  If your lower unit grease has ANY water in it or comes out looking like coffee double cream, head for your dealer immediately and get your lower unit checked.  Water in your lower unit will lead to freeze damage and will lead to excessive wear and gear failure. 
Oh, and that slightly dented or nicked up prop you've got....get it fixed.  Just imagine putting a 1/2 ounce weight on one blade of a ceiling fan and then turning the fan on High.  It won't take long for the out-of-balance condition to tear the fan apart.  It also won't take long for that out-of-balance prop to cause serious if not catastrophic consequences to your motor.  One more tip....when changing your lower unit lube always keep track of the little washers behind your fill/drain screws.  If you lose one you are going to get a water leak in your lower unit.

Storing Your Motor:
If your are not fortunate enough to live in a climate that allows boating 12 months of the year, then you are faced with storing your outboard.  Nothing causes more problems with an otherwise mechanically sound outboard than improper storage.  I like to do my routine maintenance prior to storage.  Just before decarbing (or fogging) my motor I like to add fuel stabilizer to my fuel.  This allows stabilized gas to permeate your motor's fuel system.  Unstabilized fuel which is allowed to sit in an outboard for over a month is the major repair cost that we see.  The resulting gum and varnish will clog up your carbs and the only way to clean them is to rebuild them.  Sorry, there is no tune up in a bottle that will do the job. 
If you are going to let the boat sit for an extended period of time I suggest you fog the engine down with a product like Mercury Marine's Storage Seal.
The process is exactly like decarbing except you don't restart the engine when you are done. 
When storing your motor in sub-freezing weather be sure that you have allowed all of the water to drain out of the engine.  Bag or store the motor's lower unit in a vertical position.  If water is left in your exhaust cavity it can freeze and break your lower unit.

Saltwater Disclaimer:
Ok, I have made some bold claims about longevity in outboards.  So that my customers and compatriots in saltwater don't call for a hanging, I must add as a postscript that this is for engines that are used almost exclusively in freshwater.  The salty stuff is incredibly destructive stuff.
So, if you do have the occasion to use your boat in saltwater you should flush and rinse it with fresh water after each outing RELIGIOUSLY!!

I hope these tips add years of problem free enjoyment to your outboard ownership!

Rico    Nichols Marine