2 stroke Oil

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TangaraToo

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I've just bought a Mercury 3.3 2 stroke. Manual states oil should be to TC-W3 spec.
Is this critical? I have several ltrs of good quality 2T oil left over from kart racing designed for high performance engines, also a litre of oil from RC model days used for 50 -100cc engines. Just want to test engine before I decide to strip it.
Thoughts?
 
TangaraToo said:
I've just bought a Mercury 3.3 2 stroke. Manual states oil should be to TC-W3 spec.
Is this critical? I have several ltrs of good quality 2T oil left over from kart racing designed for high performance engines, also a litre of oil from RC model days used for 50 -100cc engines. Just want to test engine before I decide to strip it.
Thoughts?
Click to expand...

Not that critical for small outboards IMHO.
2T oil for aircooled engines is ITYWF slightly heavier because they operate at higher temperatures but absolutely no problem for just testing.

I can remember when I used ordinary SAE 30 oil at 10:1 in my Seagull. 30 years on and I am sure the smoke sill lingers around Hardway
 
Use what the manufacturers spec. Your kart and rc oil is designed to be burnt at high temperatures in an air cooled engine. Your mariner is low temperature water cooled. there is a difference. Running up in your test tank occasionally is ok but i wouldn't use it regularly. Only my opinion
 
steve66 said:
Use what the manufacturers spec. Your kart and rc oil is designed to be burnt at high temperatures in an air cooled engine. Your mariner is low temperature water cooled. there is a difference. Running up in your test tank occasionally is ok but i wouldn't use it regularly. Only my opinion
Click to expand...

Dont know how long the op has been kart racing for but most Kart Racers have been forced more and more to water cooled engines in the 100cc categories. Very few air cooled now mainly because of the noise levels that have to be met at race circuits. He will certainly have to get used to mixing a lot less oil with his fuel. I think we used to race with a 12 to 1 ratio and you were lucky to see through the fog left on the start line when all the engines cleared after a slow rolling prestart lap! The oil in a kart engine was predominantly used for engine cooling as they were typically run extremely lean and with loads of ignition advance to give bottom end grunt. Hand choking the air box was a must after a long straight to avoid engine seizing!

Its a few years since I raced karts and I am still using up the left over oil in my 2t ob To the op just like karts as long as you can see some smoke in the exhaust you will be fine!
 
I've just been looking up TC-W3. From what I've read you can safely use it in your outboard, but wouldn't be wise to let it anywhere near a racing go-kart. So a racing go-kart oil should be way over-specced for a low-tuned little outboard.
There are, of course, other considerations, such as resistance to plug fouling, biodegradability etc, should these be of interest.
More info here for insomniac petrol heads: http://www.sea-doo.net/techarticles/oil/oil.htm
 
Yes the main problem with high spec oils is likely to be plug fouling particularly on a water cooled engine. Go Kart and motorcycle engines run much hotter, so the oils are designed to cope with that. A slow water cooled outboard may not be able to burn all the oil, but for short term testing, not an issue.
 
I have the same engine, and a cautionary tale.

Last spring I bought some pre-mixed 50:1 2-T fuel when buying a new chain saw. This fuel was very fancy - called 'Aspen' and £18 a gallon - but claimed a shelf-life of several years and no gummy residues so I thought I'd try it in the outboard despite the 2 stroke oil being a synthetic one designed for air-cooled engines. I too thought that a small o/b would hardly be a demanding application.

First time I topped up the new fuel was mixed maybe 50% with old, so 1:100 of 'outboard' 2T oil. All was well and the engine ran fine. I ran it dry by mistake and then filled up with 100% of the Aspen. Within 3 minutes there was a terminal sounding bang from the engine and it stopped dead. To cut a long story short it was the piston ring which had snapped. Now this might be coincidence and it due to go any second, but my single experience is that first time I tried 2T oil for high revving air-cooled engines in my Mercury 3.3 it went bang...

The chain saw is running perfectly on the synthetic fuel and oil.
 
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