mixing TCW3 oils

BogMonster · 27 December 2007, 14:56

I have, up to now, been running my outboard using Shell TCW3 2 stroke oil. I've got the chance to switch to Castrol Outboard 2T which is quite a bit cheaper. I assume if they are the same TCW3 grade, there should be no problem with mixing the two in the tank, but just thought I would ask!

Ta

Nos4r2 · 27 December 2007, 15:35

Personally I'd run the tank as low as possible then top up with new stuff while out but there shouldn't be any issues as long as neither are synthetic. We always used to try and avoid mixing brands on bikes.

BogMonster · 28 December 2007, 15:07

Not sure if they are synthetic or not, and I threw the last empty shell bottle out a few weeks ago... the best I can find on Google is "Nautilus is fully compatible with all other TC-W3 and TC-W II lubricants to eliminate any risk of operating mishaps." The Castrol Outboard 2T is definitely a mineral oil, just found that via Google.

I got an oil alarm while out this morning and the tank is nearly empty so I guess I am about to find out - I will go and get some of the Castrol stuff but will hold fire from tipping it in the tank in case anybody comes back with a "Noooooooo" in the next couple of days

As you say conventional wisdom with 4 stroke engine oils is to try not to mix them, hence the question - but I've never really been sure whether it does any harm or not, I've just tried not to do it.

Thanks

codprawn · 29 December 2007, 16:12

I have never wrecked an engine by topping up with a different oil. It has to be better than the people like my girlfriend who firstly let her Smart car run so low of oil that the hydraulic tappets would no longer tap. After giving her a row her 2nd trick was to top up with oil - a full 5 litres of it!!! The Smart only takes about 3......

Tim M · 29 December 2007, 18:40

I really wouldnt worry. An old school 2 stroke will run on just about anything. I dont normally bother measuring oil for my 15hp Mariner - just put a slug in and it runs fine! It's currently running on a tank of fuel that we found in a shed which we know is at least 3 years old. Still starts 1st time too!

mdt · 30 December 2007, 07:30

Quote:

Originally Posted by codprawn

It has to be better than the people like my girlfriend who firstly let her Smart car run so low of oil that the hydraulic tappets would no longer tap. After giving her a row her 2nd trick was to top up with oil - a full 5 litres of it!!! The Smart only takes about 3......

ah but did she fill it via the dip-stick hole as my sister did to her car... when I pointed out where she had gone wrong. "oh that took me over an hour to do my way" yep she is blonde... and it looked like most of it went down the outside of the block....

David G · 30 December 2007, 09:40

Reminds me of this story:

A few days ago I was having some work done at my local garage. A blonde came in and asked for a seven-ten. We all looked at each other and another customer asked, "What is a seven-ten?"

She replied, "You know, the little piece in the middle of the engine, I have lost it and need a new one." She replied that she did not know exactly what it was, but this piece had always been there.

The mechanic gave her a piece of paper and a pen and asked her to draw what the piece looked like. She drew a circle and in the middle of it wrote 710.

He then took her over to another car which had its hood up and asked "Is there a 710 on this car?"

She pointed and said, "Of course, its right there."

This is what she pointed to...

Dirk Diggler · 30 December 2007, 10:00

Quote:

Originally Posted by mdt

ah but did she fill it via the dip-stick hole as my sister did

The old one's are the best.

BogMonster · 30 December 2007, 13:37

Quote:

Originally Posted by codprawn

I have never wrecked an engine by topping up with a different oil. It has to be better than the people like my girlfriend who firstly let her Smart car run so low of oil that the hydraulic tappets would no longer tap. After giving her a row her 2nd trick was to top up with oil - a full 5 litres of it!!! The Smart only takes about 3......

I find if they are that low on oil the tappets actually tap quite a lot

Done it now so will find out if it goes bang on 1st January which is the next scheduled outing to watch the annual mayhem that goes by the name of the Raft Race

codprawn · 30 December 2007, 17:16

Quote:

Originally Posted by mdt

ah but did she fill it via the dip-stick hole as my sister did to her car... when I pointed out where she had gone wrong. "oh that took me over an hour to do my way" yep she is blonde... and it looked like most of it went down the outside of the block....

Funnily enough my girlfriend is blonde as well - VERY!!! It doesn't help the Smart car doesn't have a drain plug on the sump so had to by a Pela oil extractor!!!

BogMonster · 02 January 2008, 09:43

I can happily confirm that there is no problem with mixing oils and in fact the boat seemed to be running better on the Castrol Outboard 2T yesterday, it seemed less inclined to foul up and misfire when idling for short periods. It was all going really well until I got back in and found some pillock had crashed into my 9 month old Defender while I was out