Tohatsu 9.8 2 stroke first time out this year

[chrissd330]

I bought a used Tohatsu a few months ago ,not used this year,should the first 12 liters of fuel be mixed at 25 to 1 as in the manual or just use 50 to 1 all the time.

[chipko]

I would also be interested in the forums expert knowledge on this.
As yourself I read this in the manual so to be on the safe side I just mixed up a couple of litres at 25:1, ran it for 20 mins in tank, discarded left over fuel, and used new fuel at 50:1 when next on the water. My engine will probably only get used once a month so always use new fuel mix with stabiliser added.

Cracking little engine though, so light and surprisingly quick with only me on board.

[willk]

If the engine was previously run in and using a 50:1 Mix then continue using that. 25:1 is for the first 10 hours only.

[chrissd330]

If I mix 12 litres it might last me 2 or 3 trips,possibly the year,not been out yet so not sure how long a tank will last.I don`t suppose a bit extra oil will matter.Next problem will be getting the fuel to the launching site 70-80 miles by car do i fill the fuel tank first or carry in large can,fumes will be the biggest problem,

[chrissd330]

Willk, So I can ignore what it says in the manual after winter storage and go 50-1 all the time.

[willk]

Originally Posted by chrissd330

If I mix 12 litres it might last me 2 or 3 trips,possibly the year,not been out yet so not sure how long a tank will last.I don`t suppose a bit extra oil will matter.Next problem will be getting the fuel to the launching site 70-80 miles by car do i fill the fuel tank first or carry in large can,fumes will be the biggest problem,

Don't mix it if you don't need it! I use a garden style 5L can to buy fresh fuel in and I mix it just before I need it, adding it to whatever is in the main 12L tank. The 12L tank will basically last you all day - the motor does 4.5L/hr at WOT, much less at lower revs. If you close the vent on the fuel can and disconnect the fuel line, you shouldn't have any fumes.

[chrissd330]

Thanks Willk,I shall keep the fuel tank full and keep topping up with my 5 litre can mixing it the day i use it,I keep a can for my lawn mower.
Thats good news about 12 litres lasting all day and 4.5 l an hour,and no fumes can`t wait to get off.

[philpot]

One other thing you can do as a fume reducer is to take a piece of polythene and a couple of rubber bands. Just before you put all the gear back into the car, place the poly over the engine connector and wrap the rubber band around the poly. I have done this for years and found it helps. A bit heath robinson perhaps but as Tesco says ' every little helps '.

Phil

[Nick Hearne]

Originally Posted by chrissd330

Thanks Willk,I shall keep the fuel tank full and keep topping up with my 5 litre can mixing it the day i use it,I keep a can for my lawn mower.
Thats good news about 12 litres lasting all day and 4.5 l an hour,and no fumes can`t wait to get off.

I hope you are not going to be using the same 2st mix as your lawnmower, as they will require different 2st oil as outboards do not run as hot as garden mashinery!

[Max...]

I've never found 12 litres lasts all day (how is all day 2-3 hours?) but I keep reading that everyone else's does!?

My Tohatsu 9.8 was not as thirsty as my Mariner 15 but in general use (ie not constant WOT) I average around 2 to 2.3 NM per litre or 8 litres an hour or so which is more than the old 10% of hp in gallons per hour (ie 6.75 for a 15). I've found that guide a bit optimistic.

[willk]

Originally Posted by Max...

I've never found 12 litres lasts all day (how is all day 2-3 hours?) but I keep reading that everyone else's does!?

My Tohatsu 9.8 was not as thirsty as my Mariner 15 but in general use (ie not constant WOT) I average around 2 to 2.3 NM per litre or 8 litres an hour or so which is more than the old 10% of hp in gallons per hour (ie 6.75 for a 15). I've found that guide a bit optimistic.

I guess that you pack more into a day than most Max!

My longest "day" in the SIB has been just under 30Nm - that's a fair old bit of bumping along. Quite a lot of the time, I pootle about quite sedately, exploring and sh1t.

My sensible top end is about 16kts (it will do 18+) but mostly I'm running around 13kts and thus saving quite a bit of gas - stretching the range of the tank. WOT on the toohotsue is 4.5l/hr - this is probably what foxed you with the 15hp comparison.

Say I did run at WOT, the tank is actually a 13L and will therefore give me 2.88 hours at 18kts = 52 Nm approx. Who's doing 50Nm in a SIB?

[Max...]

Last trip was 26 NM and used 12 litres, before that 38 NM and 16.5 litres. According to the formula at WOT it should use 6.75 litres an hour but doesn't work for me, to be safe I need to guage 8 litres an hour minimum regardless of speed.

In the 26nm trip we were out for most of the day but 'moving' for 3.5 hrs at average of 7.2 but this is probably slewed by the GPS registering when the boat was moored.

Cannot remember the old Tohatsu figures but I think the 4.5 litres an hour was close.

Anyway, in a 'day', say actual

[chrissd330]

Hi Nick,the lawnmower is a 4 stroke,but i was thinking at the end of the season any left over 2 stroke fuel could go into the chainsaw or hedgetrimmer to get rid of it,but as you say garden machinery runs hotter than outboards so thats out,so could i use it the following year?How long does 2 stroke fuel last?

[chrissd330]

Phil,thanks for the tip of covering the engine connector with polythene and elastic bands it all helps.
chris

[willk]

Originally Posted by chrissd330

Hi Nick,the lawnmower is a 4 stroke,but i was thinking at the end of the season any left over 2 stroke fuel could go into the chainsaw or hedgetrimmer to get rid of it,but as you say garden machinery runs hotter than outboards so thats out,so could i use it the following year?How long does 2 stroke fuel last?

I chuck some into my diesel vehicle - maybe 2 liters in 80? The rest I add to 50% fresh in the spring and it seems to work just fine.

Top tip - don't mix that last 5L tank in the autumn - take the 5L tank of straight gas and a 100ml shot of marine two stroke and mix it IF you need it - not before...

[Nick Hearne]

Originally Posted by willk

I guess that you pack more into a day than most Max!

My longest "day" in the SIB has been just under 30Nm - that's a fair old bit of bumping along. Quite a lot of the time, I pootle about quite sedately, exploring and sh1t.

My sensible top end is about 16kts (it will do 18+) but mostly I'm running around 13kts and thus saving quite a bit of gas - stretching the range of the tank. WOT on the toohotsue is 4.5l/hr - this is probably what foxed you with the 15hp comparison.

Say I did run at WOT, the tank is actually a 13L and will therefore give me 2.88 hours at 18kts = 52 Nm approx. Who's doing 50Nm in a SIB?

Last day out in the sib 65 miles
http://www.rib.net/forum/f50/friday-...les-63441.html

[Nick Hearne]

Originally Posted by chrissd330

Hi Nick,the lawnmower is a 4 stroke,but i was thinking at the end of the season any left over 2 stroke fuel could go into the chainsaw or hedgetrimmer to get rid of it,but as you say garden machinery runs hotter than outboards so thats out,so could i use it the following year?How long does 2 stroke fuel last?

I have never had a problem running last years fuel pre mixed or not!

[Max...]

My old 2 stroke fuel always goes in the lawnmower, before that it went in the old Ford Focus - long gone now and we're all diesel now though so the lawn gets cut a lot...