Out board 2 stroke oil

[pcatterall]

After being admonished by an old salt and told that I must use outboard 2 stroke oil in my outboard as 'outboards run cooler than air cooled jobbies so need special oil, I have always searched out outboard oil.
Now the chandler at Conwy tells me that this is rubbish and any 2 stroke oil will do.
What does the panel think??

 

[ctelfer38]

Thank you for asking that. I want to know as well. Having just resurrected my old Seagull, I have also noted the advice of the horrors awaiting me unless marine 2stroke is used. Having done the test runs on the bench with the prop in the Dustbin of water, the old girl seems to run just fine with some unleaded and the appropriate dash of lawnmower oil I happen to have in the workshop. Somehow I feel that the Seagull is not such a fragile beast that it is bothered what I use. Am I wrong? /forums/images/graemlins/cool.gif

 

[itsonlymoney]

Never had a problem with bog standard oil. Think you have been misinformed. IMO

 

[VicS]

Strictly speaking the correct advice is that you use an oil to an API TC-W specification. TC-W3 being the latest. For those with a strong environmental conscience there are biodegradable versions.

I did compare "outboard oil" with motor cycle oil many years ago in the laboratory and I found that the motorcycle oil had a slightly higher viscosity presumably because it would be operating at higher temperatures.

You will find however that some brands of other two stroke oils are labelled as suitable for small outboards.

Most if not all Seagulls predate "outboard oils" and the TC-W specs. Indeed the oils listed as suitable for mine from 1973 and 74 are all simply two stroke oils as would have been used in motorcycles at the time. Castrol TT for example. A straight non detergent SAE 30 oil was also said to be suitable if the two stroke oils are not available. (I did for a time run my 40+ using SAE 30 oil and believe you me the smoke when mixed at 10:1 was quite impressive!) TC-W3 is the current recommendation however.

For small outboards I suggest it matters not but at the quantity of oil one would use in a season the additional cost will make an insignificant increase in the overall boating budget for the year.

For larger high powered outboards used at high speed I suggest you should stick with the makers recommendations. The cost of the oil is peanuts compared with the cost of some of those engines.

To draw a parallel, if you run a cheap old banger of a car you will probably buy cheap oil for it from a supermarket or wherever. If you run an expensive high power machine costing many £10K and you discover the garage that does the servicing is ignoring the manufacturers recommendations and putting any old cheap oil in it you'd kick their arses I suspect.

I now use TC-W3 oil for the outboards, Seagulls included, and "garden machinery" oil for the mowers.

 

[ctelfer38]

Very helpful. Thank you. /forums/images/graemlins/cool.gif

 

[jwilson]

In the 1960s when I bought a Seagull brand new the manual said to use straight 30 grade motor oil, and very sternly admonished me NEVER to run it on less than 10:1 mix. I kept it 20 years, and it was the most reliable bit if machinery I've ever owned, but also horribly oily, smoky etc.

 

[alb40]

Ive always used quicksilver outboard oil in all my outboards.

In the chandlery, it is a fiver a bottle. Halfords motorbike oil is a tenner! Both 1 litre bottles. So for me, it is alot cheaper to use the proper stuff when bought round here.

The quicksilver oils also come in bigger (5lt?) bottles, which are actually good value for money, and last ages.

It is true that the oil is designed for the cooler temperatures. Some oil i bought in wilkingsons says on the back 'only suitable for air cooled outboards', which i assume is due to the running temperatures. It just mean that the proper stuff helps the engine run cleaner with less smoke, especially at lower revs.

 

[pcatterall]

Thanks, guys for the comments. Good stuff Vic, it is always useful to get the real facts with a practical conclusion.
So I will use outboard oil in my outboard and 'ordinary' oil in my genny but not worry too much if I occaisionally use the wrong one!!

 

[FullCircle]

There is a difference between modern motorcycle oil and strimmer/chain saw oil. The latest motorcycle emissions technology meant the oil had anti ashing additives to keep the combustion chamber clean burn. The bearings, oil metering pump and all internal surfaces in the engine are designed for this oil, which do not have the same lubrication props as 'ordinary', and as such are actually less good for your engine despite being twice the price.

I have a Yamaha RD 350 from 1973, and it is run on strimmer oil, as the modern anti ashing formulas make mine over hot and shorten bearing life.
I had an Aprilia RS250 which smoked like hell when I tried it on strimmer oil. It was also 5 mph slower.

 

[VicS]

[ QUOTE ]
Some oil i bought in wilkingsons says on the back 'only suitable for air cooled outboards'

[/ QUOTE ] That is interesting, I often wondered about them. Presumably thats not oil sold specifically for air cooled outboards but for small air cooled two stoke engines in general. [ QUOTE ]
In the 1960s when I bought a Seagull brand new the manual said to use straight 30 grade motor oil, and very sternly admonished me NEVER to run it on less than 10:1 mix

[/ QUOTE ] The current recommendation would be to run it on TC-W3 oil but to contiue with a 10:1 mix. From 1968, I think, they had slightly larger bearings and could be converted to run on a 25:1 mix. From '78 they came set to run on 25:1 anyway. Full details are on the Saving old Seagulls website

 

[alb40]

[ QUOTE ]
[ QUOTE ]
Some oil i bought in wilkingsons says on the back 'only suitable for air cooled outboards'

[/ QUOTE ] That is interesting, I often wondered about them. Presumably thats not oil sold specifically for air cooled outboards but for small air cooled two stoke engines in general. [ QUOTE ]


The bottle just says '2 stroke engine oil'. The back label says more but i cant remember what it all says. It does specifically say air cooled outboards, or not suitable for water cooled outboards requiring TC-W oil, or something like that.

I've used it in the seguall with no issues, but it makes my mariner 4 very smoky and oils up quickly. On quicksilver oil it does not smoke at all so there clearly is a difference based on running temperature.

 

[oldharry]

The theory is that a water colled outboard runs much cooler and slower than the modern 2T motorcycle engine, and the oils - as Vic found are formulated to work best the different temperatures, and with different 'ash' properties. TWC3 is forumlated so as to burn as much of the oil off as possible at outboard working temperatures. This reduces the possibility of plug fouling, and reduces the amount of unburnt oil that passes through the engine into the environment.

I once used outboard oil in a high revving motorbike because I didn't have anything else, and it fouled the plugs every 20 miles or so by growing a hard metallic whisker that would short out the plug, across the gap. Reverting to 'proper' oil, all was well.

At the modern 100:1 ratio I dont think the increased level of oil emission will make a significant difference, and is unlikely to foul the plug anyway.

Seagulls come in a different category: the oil not only lebricates the engine, but actually seals the main bearings in the crankcase - according to the SOS site. Thick engine oil is therefore called for! And liberally spewed out of the exhaust ....

So chuck that old Seagull, as it will pollute the harbour quicker than a dozen or more modern 2T's running at the same time even on the wrong oil! /forums/images/graemlins/laugh.gif