oil

i have a 1974 mercury inline 6 115 h.p. engine that takes 50:1 mix.what's the difference between regular two stroke oil and the 50:1 oil?They both call for the same amount of oil to be mixed with the gas.There is some that say 100:1 oil can that be used in a 50:1 engine.

Re: oil

Some oils are designed to be run at richer mixtures, such as 24:1, or 32:1, and an oil that says 50:1 is designed to be mixed at that rate.<br />This being said, look for a TC-W3 rating on the oil for best results.<br /><br />Edit: At this point, I would NOT recommend any oil be run at 100:1 cause it won't work very long.

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All Mercs are 50:1 As Walley said.. don't mix it richer or leaner than that. <br /> http://www.tohatsu.com/tech_info/oil_gas.html <br />You can mix up 2 stroke fuel (Non Outboard) for your chainsaw and other non-critical machines and they will run fine,even if you use the wrong ratio or cheap oil.. but with a 2 stroke Outboard, there are special formulas made to a Marine Standard.<br />It will be labelled "Outboard 2 stroke oil" or similar<br /><br />Use the best you can get and add a fuel stabiliser for longer storage. That Merc will then serve you well.

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Like Walleyehed said, use what the manufacturer recommends as far as mix ratio. 50:1 is the standard, but there are oils that are designed to be mixed at 100:1. You will not do any harm to your engine at that ratio, as long as it is designed to be mixed at that ratio.<br /><br />Dave

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I beg to differ, Unicorn, emphatically!<br /><br />Your advice on using quality TCW-3 oil in a carbureted water cooled 2 stroke is satisfactory. <br /><br />It is wrong for a DFI engine. Use DFI oil only.<br /><br />Your advice on air cooled two strokes is very wrong. <br /><br />Air cooled 2 strokes run at much higher temperatures and rpm than outboards. 500*F head temp and 10,000rpm are not unusual. Most chainsaw engines are Swiss watches compared to the usual outboard.<br /><br />They require a higher temp, higher viscosity oil, and the mix is critical .<br /><br />Get the mix wrong or use TCW-3 and you will roast your chainsaw or other high speed, air cooled 2 stroke.

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well i'm a little confused on this because i have a bottle that says it's 50:1 on the front but on the back it says all the ratios it can be mixed,like 24:1, 32:1 and so on.

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Sorry for the confusion ..all<br />This is what I meant.<br />For a 1974 non oil or fuel injected Mercury 2 stroke (Like yours) that uses pre-mix fuel. You need "Outboard 2 stroke oil".<br />For a Mercury, you must mix it 50 parts petrol to 1 part oil.<br />If the oil you have is NOT outboard oil, you can use it for pre-mix in a 2 stroke chain saw or lawn mower (mixed at the right ratio) eg 20:1 or 25:1, but my 20:1 chainsaw is rarely mixed right.. (Usually too oily) but is only worth $100.00 not $5000. So, to me it is not critical.<br />So, if your oil is outboard oil, you can mix it 50:1 and use it in your Merc.<br />As far as I can see, nobody has recommended TCW3 oil for a chainsaw.

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i610288, oil can be mixed in ANY ratio richer than the rating it was given for a different application, however, it CANNOT or SHOULD NOT be mixed in a leaner ratio than specified on the container....ie, 50:1 can be used for all mixtures UP TO 50:1, and yes, general 2-stroke oil is NOT the same as marine TC-W3, and I would not recommend using general in an outboard, nor would I recommend TC-W3 in a chain saw, although the "better" marine grades work for that application if needed.<br />There are many different types of equipment requiring 2-stroke lubes, and the best method in reality, and common sense is using what the manufacturer suggests-at that point you are atleast "meeting" the manufacturers requirments.<br /><br />Edit: i610288, now there should be no confussion on this.

Re: oil

i610288,on your outboard, use a TCW-3 oil rated for 2 stroke outboard engines.Premix ratio 50:1, and if i were you i'd just forget about all that other stuff, or you'll most definetly end up terrible headache.

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Outboard engines are characterized by their constant speed, high output operation. They are usually set at a desired high speed and continue at that speed until the destination is reached and then throttled down. Also, they are constantly cooled with fresh, cool, non-recirculated water. Chain saws, on the other hand, are a high action operation. They are constantly started and stopped, used for short periods and frequent overloads are its hard place in life. Additionally they have smaller displacements than outboards and are air-cooled. By understanding how the operation of an engine can affect the oil used and how an oil can affect the engine, we can better appreciate the difference between a water cooled two-cycle oil and one formulated for an air-cooled two-cycle engine.<br /><br />Water-cooled two-cycle engine oils require higher levels of a heavy oil to prevent piston and cylinder wall scuffing. Because of their high average piston temperature, lighter oils evaporate too quickly from the piston cylinder contact area. The heavy base oil, which vaporizes at very high temperatures, resists evaporation and remains in place to provide lubrication to the piston and cylinder. Air-cooled oil formulations must have much lower levels of the heavy base oil than water-cooled engine oils. These oils require only a small amount of heavy oil to pro vide protection against piston scuffing and seizure at peak temperatures. Heavy levels of heavy base oils in an oil formulated for air-cooled engines can cause engines deposits. <br /><br />These deposits form as a result of incomplete burning of the heavy oil. The deposits can cause piston ring sticking and can eventually plug or disrupt the flow of the exhaust system, resulting in power loss and possible engine damage. Detergent additives should not be used in water-cooled two-cycle oil formulations. When burned with the fuel, detergents can produce an ash deposit in the cylinders. This ash deposit can possibly foul spark plugs, form exhaust port deposits which cause loss of power, and possibly create cylinder hot spots that can cause destructive pre-ignition.<br /><br />Now with that said, Use a TC-W 3 or one specified for that use in your outboard!!<br /><br />I recomend a synthetic, as you get better all around performance, cleaner burning, less (almost no) Sparkplug fowling! I have in the past used a 100:1 synthetic oil with great results in an 85 HP Evenrude outboard! I however mixed it at 80:1! I beleive there are even better synthetic TC-W 3 specific synthetic oils now! Racing synthetics should not ever be used in outboards as they do not get hot enough to burn them off completly (unless it is being used for racing or maybe a bass boat that is run at WOT most of the time)!<br /><br />LubeDude

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LubeDude <br /><br />Just curious, what brand synthetic oil did you use in the Johnson at 80:1 and how long did you run it like that? I mean was it for years or weeks or... I am trying to get an idea of just how good the synthetics are. I keep hearing about amsoil, but not sure which to use. Also, Mobil 1 has been talked about as an alternative to dino. What do you think?

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The oil I used at 80:1 Was the Amsoil 100:1! This was way back in the late 70s! the engine was on a 15' Ranger Bass boat! I ran it that way at 80:1 for two tournament seasons! It was either Idle or WOT all the time! I literally ran the H*ll out of that boat, I honestly wanted it to blow up so I could put a 115 on it! I changed the plugs at the end of the first year as I didnt know how old they were! (I wouldnt have had to though) as they were in great shape, very clean and no fowling at all just a nice brown color! I bought the Boat used and it had a lot of hours on it allready! I changed the lower unit oil and the engine oil after i had the boat for about a month so I knew how well It performed on regular 2 cycle oil! I took it to the lake one day with a fresh tank of gass with the amsoil in it! I took it out and wrote down all the RPMs and speed of the boat! I then came back and changed the tank over and changed the lower unit oil! Went back out and ran around for about 15-20 min and then put it though its paces! I couldnt beleive the difference just changing to synthetic oil made! I gained 3-400 RPM at WOT, I had another prop back at the dock so I changed it and whith everything I gained 3-4 MPH! Thats a lot in a boat of that size! It would run 49-50 MPH at 5800-6000 all day long! I cant say for sure that everyone will experience such dramatic results, as every engine boat combination is different!! But that sold me on synthetics! <br /><br />Im going to use Amsoil in my Merc 150, Premix this next summer! Im going to use the AIO Injection oil as a premix!<br /><br />If it is the Mobil MX2T Synthetic you are talking about, It is not recomended as a TC-W3 aplication oil, I would concider it a racing oil more designed as a n MX Motorcycle or quad oil! It is a very good oil for that! Or are you talking about using synthetics in vehicles??<br /><br />I like the 100:1 oil as a small engine, air or water cooled oil, small outboards used for trolling, lawn and garden and chainsaws!<br /><br /> It is really NOT my intention to sell here on the forum, just to offer help, but If you do not have a local dealer, contact me at my home page! My Email is there too!<br /><br />LubeDude

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So you ran synthetic in both the fuel/oil mixture and the lower unit?

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Synthetic gear oils, I beleive all of them have anti foaming agents that will be fine for lower units in boats! Not all Dino automotive gear oils have them in suficient quantities, so do not use them! Gear oils that are manufactured for lower units will perform satisfactory! Synthetics will protect your gears and bearings better if you should get moisture in there and not notice for awhile! Not to mention less gear and bearing wear, better performance in cold weather and in worm, (afterall, where is your lower unit)?<br /><br />In a Word, YES!!!<br /><br />LubeDude

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Thanks for the info! Very informative and quite interesting story you mentioned. I believe I will give it a go in the spring and see how it performs.

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There are other good Synthetics out there, I think Penzoils synthetic outboard oil is a decent oil, I just like what I use!<br /><br />It is actually a religon ya know!<br /><br />LubeDude

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Where does one get Amsoil? I don't recall seeing it anywhere. And is there a specific one to get, outside of "outboard oil"?

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Rick,<br /><br />Contact LubeDude via his homepage (check his "profile"). His email addy is at the bottom....<br /><br />Dean

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Amsoil is usually sold by individual dealers, like (no offense) Tupperware or AmWay.

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rosco:<br /><br />What you say is true, But the Amsoil dealers I know are very different than othe ML Dealers, Generally they really know there products and are not pushy! They have a very fine Product to offer! I Myself see it as a disrespectfull remark to place them into that catagory!!<br /><br />Hasbeen