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Two Cycle Oil

2/2/00

Two Cycle Oil for Outdoor Power Equipment

Seems there is some confusion these days as to what oil should be used in todays outdoor power equipment with 2 cycle engines. I'll try to explain it as simply as I can. I'm not a chemist so I can't go into specific formulation detail of how that formulation works, it probably wouldn't make any more sense to you then it would to me. Just the basics are all that are needed.

You're going to see fancy ratings such as B.I.A. or ISO-L-EGD and JASO M345 thrown at you to convince you that someone's oil is what you should use. Well, B.I.A. is the boating industries standard and to the best of my knowledge hasn't been substantially upgaded since the 50's. That's not to say the oil with this rating hasn't been impoved over the years, certainly it has. The problem with it is you have no assurance by the rating alone that it will work properly in air cooled outdoor power equipment.

2 cycle oil is deigned to be burned with the fuel as cleanly as possible after having done it's job of lubricating the engine. Water cooled boat motors or liquid cooled motorcycles and atv's run much cooler and a much slower rpm then air cooled outdoor power equipment. Your chain saw or line trimmer need an oil that will not only protect the engine at faster rpm's and higher temps but burn clean in those conditions without coating the piston, rings and cylinder with unburned or half burned goo which will seize it. Likewise, a boat engine may not recieve proper protection from oil formlated for air cooled outdoor power equipment for the same reasons, in reverse. The ISO-L-EGD and JASO M345 ratings are the result of the outdoor power equipment industries need to assure that todays high rpm, high temp engines recieve the protection they need. They are formulated for todays outdoor power equipment with the additional intent of helping to meet the new emission standards of C.A.R.B., E.P.A. and U.L.G.E. That's, California Air Resources Board, Environmental Protection Agency and Utility Lawn and Garden Equipment. Another bureaucratic mouthful.

Currently, only the oils from ECHO and HUSQVARNA meet those standards. Stihl claims their oil is as good but hasn't had their oil certified. Perhaps they feel their engines burn clean enough without the costly certification attached to their oil, I really don't know. In any case, Stihl engines crank out some of the highest rpm's in the industry and their engines do just fine with their oil.

Just about every manufacturer has an oil company producing oil with their name on it and to their specifications. While your equipment is under warranty it may be best to use their oil just to cover yourself. If you have multiple brands and don't wish to mix multiple batches of fuel/oil mix, go with Husqvarna or Echo. After warranty, add Stihl to the list. These manufacturers have the highest output engines on the market today and need the highest level of air cooled engine protecion available and their oils will get the job done in any modern air cooled 2 cycle outdoor power equipment.

So long as you use an oil designed for todays modern 2 cycle air cooled equipment, you shouldn't have an oil related failure. The rest is up to you. Making the proper fuel/oil mix is critical. Most oils today are designed for a 50-1 ratio. One gallon of gas is 128 fluid ozs. That will require 2.56 ozs of two cycle oil, rounding off to 2.5 is a safe bet. Thats not much oil in a gallon of gas so you can maybe better understand the need to use the proper quality oil. Too much will cause plug fouling, carbon build up and partially burned oil that burns into the piston and cylinder causing the engine to overheat. Overheating is one of the major causes of failures in two cycle engines.
Too light on the oil mix will not lubricated properly and again cause, overheating. Overheating causes metal to expand and then you have a seizure.

Old fuel also doesn't burn clean and leaves a burnt residue on the piston and cylinder and results in a very similar condition as too much oil or a boat oil. End result, seizure. 30 days is the limit for fuel before it's too old. Mix no more then a gallon at a time, unless you're a commercial user, and at the end of each month dump what's left into your car when it has a full tank. The dilution of a half gallon of mixed fuel or what ever was left in to your cars full tank isn't going to hurt your car and you'll be able to use up all your fuel without wasteing it. However, if you've got gas that's been sitting for months and smells like something evil, take it to a recycler rather then putting it in your car.

Yes, you may have to come to a shop like the one I work for to get good quality oil as you aren't likely to find it at your gas station or supermarket, but like the old commercial goes; You can pay me now or, uh, you get the message.

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