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Old 07 September 2011, 22:29   #1
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Country: UK - England
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Newbie looking for a bit of 2T knowledge!

Hi all, first of all great forum, loads of good stuff.

Picked up first boat yesterday (zapcat) running a Tohatsu 50Hp 2 stroke. Engine is 01 model. (carb'd triple).
Am totally new to outboards so would really appreciate a bit of help.
Am planning to run at 50:1, only using for fun so would rather run a bit rich and sacrifice a few ponies than risk going lean, thought maybe even of 45:1 but dont want to be fouling plugs - am i in the ball park?

second question - 2 stroke oil - i have read TCW3 (i think i remembered that right) is the only spec to run, is this different to any other premix, Is marine premix somehow different to other types? I was planning on using silkolene fully synth bike premix, as i know its good stuff.

Final question, pre and post outing maintenance, what is recommended, its going to be salt water use, all i know so far is to flush the engine, but would love to know if there are any particular areas that want regular greasing/attention.

Sorry to start with a load of questions, but its so much cheaper and easier to learn before you make the mistakes!!

Thanks in advance

Dave
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Old 07 September 2011, 23:16   #2
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Quote:
Originally Posted by burners View Post
2 stroke oil - i have read TCW3 (i think i remembered that right) is the only spec to run, is this different to any other premix, Is marine premix somehow different to other types? I was planning on using silkolene fully synth bike premix, as i know its good stuff
Whisky is good stuff too but you should use TCW3 or say bye-bye to yer motor.

A good flush and wash down is fine. Use some anticorrosion spray on the block too, if you wet it often. Zapcats
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Old 07 September 2011, 23:31   #3
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The TCW3 thing is not just marketing hype! The difference between marine 2 stroke and "land" 2 stroke is the temperature the engine runs at. Outboards are water cooled so run much cooler and therefore need different oil. TCW3 needn't be expensive if it doesn't have a famous brand name on it.
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Old 08 September 2011, 05:38   #4
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Quote:
Originally Posted by burners View Post

second question - 2 stroke oil - i have read TCW3 (i think i remembered that right) is the only spec to run, is this different to any other premix, Is marine premix somehow different to other types? I was planning on using silkolene fully synth bike premix, as i know its good stuff.
Silkolene is good stuff - They also do marine TC3 2t product called "Aqua"
Tohatsu also have their own brand of TC3 2t oil, I have used both

Hope this helps...
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Old 08 September 2011, 09:35   #5
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Welcome!

Also an O/B runs at high rpm for long periods of time under constant load, whereas a motorbike is cycling up & down the rev range, and as it goes up & down hill the load increases & decreases. Hence use of TCW3

Run it at 50:1. If not you'll just end up with a smoking thing that can't pull the skin off a rice pudding and that will blacken your hands with soot every time to go anywhere near the leg to flush it! Just remember with a tank that when you add the oil, it's not as simple as you might think - to keep the maths simple, think of a 50L tank. That might imply you want a litre of oil, but the oil takes up 1/51st of the volume.... I worked out for a 30L tank if you added 600Ml to a 30L tank you have just added an extra 20ML. Now, you'll never totally empty the tank, so say you only half empty it, then top uit up for next time - there's 10 exra ML in there..... you do it again......

I run with 2 tanks, and always tip the mortal remains of the first into the second before I top them up so that at least one tank is starting from fresh. I then use the second tank first the next time.......
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Old 08 September 2011, 16:00   #6
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Hi Guys,

All really useful thanks.

Am heading out this weekend down protsmouth way for a first outing - may have a few more questions after that, hopefully nothing too major though! Have looked around for a full spec manual for the engine, as going to pull the pistons this winter and replace rings and cx pistons for wear, but not been able to find tolerances, dont spose anyone knows where to look?
cheers.
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Old 09 September 2011, 11:17   #7
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No idea about dimensions fot the Tohatsu, but if you are looking for repalacement bits, Mallory or Sierra seem to cover most. I now have a set of Mallorys in the Merc.

Instead of a total teardown, if you remove the exhaust port, can look in & see what state the walls & rings are in. Do a compression test as well, that will likely give you enough info to make the pull / not pull decision.
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Old 09 September 2011, 12:40   #8
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Tohatsu 50hp 2001. 50:1 premix??

Im not sure if this engine should be an auto lube?? my old twatso 50 was.
Have you checked for a seperate oil tank under the hood...
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Old 09 September 2011, 13:58   #9
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Quote:
Originally Posted by 9D280 View Post
Welcome!

Also an O/B runs at high rpm for long periods of time under constant load, whereas a motorbike is cycling up & down the rev range, and as it goes up & down hill the load increases & decreases. Hence use of TCW3

Run it at 50:1. If not you'll just end up with a smoking thing that can't pull the skin off a rice pudding and that will blacken your hands with soot every time to go anywhere near the leg to flush it! Just remember with a tank that when you add the oil, it's not as simple as you might think - to keep the maths simple, think of a 50L tank. That might imply you want a litre of oil, but the oil takes up 1/51st of the volume.... I worked out for a 30L tank if you added 600Ml to a 30L tank you have just added an extra 20ML. Now, you'll never totally empty the tank, so say you only half empty it, then top uit up for next time - there's 10 exra ML in there..... you do it again......

I run with 2 tanks, and always tip the mortal remains of the first into the second before I top them up so that at least one tank is starting from fresh. I then use the second tank first the next time.......

Not sure that works does it?
50:1 means 50/51 of one and 1/51 of the other, so it should be 50 litres of fuel and 1 litre of 2 stroke to give a total of 51 litres...
If you always mix the additional mix externally, and then add it to what remains in the tank you should always retain the correct mix...

Alasdair
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Old 09 September 2011, 14:22   #10
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Tohatsu branded oil is made by rock oil, semi synthetic TCW3.
I believe Rock MP3 is the same oil without the Tohatsu sticker.
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Old 09 September 2011, 15:14   #11
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Hi burners, regarding power output. A good friend informs me that power output increases as you increase the proportion of oil, right up to the point it oils yer plugs. But in practice, out on the water, 100/1 and the correct prop will easily give you enough power to scare yourself and your mates witless! Always use the marine grade oil, brand doesn't matter, it's down to whats available locally. Also, check out the australian thundercat forum, masses of tech stuff relating to these boats. Finally, enjoy your cat!
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Old 12 September 2011, 09:45   #12
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Not sure that works does it?
50:1 means 50/51 of one and 1/51 of the other, so it should be 50 litres of fuel and 1 litre of 2 stroke to give a total of 51 litres...
Have you ever tried getting 51 litres into a 50L tank? (or in my case 30.6L into a 30L tank...) Bottom line is you still need to work out the proportion of oil for the given volume of tank, then top up with fuel.

Quote:
Originally Posted by akirk View Post
If you always mix the additional mix externally,
And there lies the problem.... in doing so I would need not only potentially 90L worth of gerry cans, but three more cross decks of fuel, which is just an invite to loose a chunk of it in spillage & add a bit more contamination to the fuel.

Hence my working out the appropriate quantities of oil for an empty portable tank. What I also didn't mention above is the two 5L tanks of premix for the Aux luking in the wings...
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Old 23 September 2011, 21:26   #13
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Quote:
Originally Posted by Seabay View Post
Silkolene is good stuff - They also do marine TC3 2t product called "Aqua"
Tohatsu also have their own brand of TC3 2t oil, I have used both

Hope this helps...
Reading this thread as a biker & boater,i thought the oil was different coz of marine enviroment stuff but as time goes on what u have said makes sense,re burn temp etc,does this explain why boat oil is blue ie ocean & bike oil is any other colour???? or am i still missing the big picture!
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Old 26 September 2011, 07:50   #14
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boat oil is blue ie ocean
Evinrude XD100 is gold coloured.....like the price
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Old 26 September 2011, 09:33   #15
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Reading this thread as a biker & boater,i thought the oil was different coz of marine enviroment stuff but as time goes on what u have said makes sense,re burn temp etc,does this explain why boat oil is blue ie ocean & bike oil is any other colour???? or am i still missing the big picture!
Nope because the aircooled 2T oil that goes in my strimmer is blue and it doesn't work at all well in the sea as you get cavitation on the cord and the revs bog down quite a bit
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