Merc 2.2 fuel mix

[Gordonmc]

I recently acquired a second hand Mercury 2.2 hp outboard which came with no paperwork.
I have been running it on a fuel mix of 1:100, but have been told a Merc 2.5 runs on 1:40.
What is the correct fuel mix?

 

[cliff]

My old merc 2.2 ran on 50:1
The new 3.3 runs on 100:1 but even the dealer said keep it on 50:1 so I would go for 50:1 unless you have the serial number then you can trace the age of the engine and find the correct mix but I am sure 50:1 is correct.

“Artificial intelligence is no match for natural stupidity”
Skype id:cliffillupo

 

[jerryat]

Yep, agree with Cliff. My Yamaha 2 says 100:1, but the marine engineer who sold it to me, said 'if you want to extend it's life hugely use 50:1, it may smoke a tiny bit, but it's far better for the engine'

Used to do this before with my Mariner 2 - and that was still working fine at 17 years old when I sold it. I'd go with 50:1 whatever the book says.

 

[Ships_Cat]

We have a 3.3 Merc which is the same engine I believe, about 4 or 5 years old. Don't recall what the manual says but we run it on 50:1. As others are saying, I too suspect you will be pretty safe at that.

John

 

[Stemar]

Is this a badge engineered Tohatsu 2 to 3 1/2 hp engine? If so the correct mix is 50 to 1

 

[cliff]

excerpt from the Mercury 3.3 owners manual recommends 100:1 for pleasure use or 50:1 for commercial use
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“Artificial intelligence is no match for natural stupidity”
Skype id:cliffillupo

 

[Ships_Cat]

Aye Cliff, after seeing that it has spurred the old brain cells here so's I can confirm that is exactly what our manual says too.

I don't use QS but a TC-W3 from a friendly oil company at 50:1 (the non QS for no good reason as QS and those from other marketers are all quite cheap here). I would still use 50:1 if I used QS.

John

 

[pappaecho]

Why do "commercial users" use 50:1 and "leisure" use 100:1. Could it be that commercial users do not take kindly to their engines fallings to bits after a couple of years? My old Seagull did 25 years of initially 16:1 then later 25:1 , and it helped save the planet by producing a pall of smoke that stopped harmful UV radiation from entering the lower earths atmosphere

 

[ShipsWoofy]

The recommendation is 100:1 but I am now also running my 2.2 on 50:1 ish!

These engines appear to destroy plugs, I am changing the spark plug it seems about every four months with weekend usage (light). It was suggested on here (PBO) to try upping the ratio to 50:1 to keep the plug cooler and try to extend it's life.

Still monitoring, the engine does seem to be about the same running wise, though I ran out of fuel a few weeks back and then could not start the engine until I had cleaned to carb bowl, whether or not that had to do with a change in mix or crud from the empty tank getting through I don't know.

It does seem the popular vote to add 50:1. Incidentally we also make sure to use only outboard 2 stroke, lawn mower and bike two stroke is designed for engines that run hotter and faster. There is no real price difference so it is not a painful choice really.

Hope this helps.

 

[cliff]

Could be commercial users don't look after their equipment as well as pleasure users. Storage, going from cold tick over to full throttle in a split second, extended running on full throttle or as near as makes no difference. So a little extra oil might help preserve the engine for a while.
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“Artificial intelligence is no match for natural stupidity”
Skype id:cliffillupo

 

[Kawasaki]

Use the "correct oil" Outboard two strokes, motorcycle, lawnmowers etc all have a different "usage cycles" ie Your bike fer instance has probably longer periods and more periods of running. Yer outbaoard, little tenderised ones have long periods of idleness and short bursts of activity, a bit like sex when your my age. Yer lawnmower comes out for 6 to 10 times a year for 1.5 hourly stints. ( Probably twice a year if you own a boat!) Self mix, for the likes of the 2.2 Merc and similar, as opposed to oil injected systems use an oil with different properties. The oil petrol mix is critical for a reason that is often overlooked. Too much oil alters the air fuel mix. Without rabbiting on and making this post more boring than it,s getting my advice is to run the engine as the Manufacturer suggests, make sure you use a self mix synthetic oil ( any make). When I was in the Motorcycle World I had experience of engine seizures because of too much oil! On the subject of spark plug consumption reference these little " ring de ding dingers" failure usually relates to the wrong heat range , gap, or oil mix. A spark plug in a spasmodically used outboard with a correct set up and "winterising" should last for seasons ie hundreds of hours. If your plug is oiling up or "whiskering" something is up, if your outboard takes more than three pulls to start ,somethings up. Correct measurement of "The Mix" is all important. /forums/images/graemlins/wink.gif This is starting to become a lecture not a "Quick reply" I,m off. /forums/images/graemlins/grin.gif

 

[VicS]

Re: Seagull fuel mix

Old seagull engines ran on 10: 1 but they could converted to 25:1 if the carburetter needle was changed. I believe the new needles are no longer available but you'll find all the info on http://www.saving-old-seagulls.co.uk/

 

[supermalc]

Re: Seagull fuel mix

Having not used premix since my early motor bike days, I was under the (mistaken) impression the leaner mixes were to engine developement. My friends now tell me they still use 25 to 1 in chainsaws, lawnmowers outboards etc. etc. and that they LAST much longer.

Having a little experience with tuning 80s Yahama 2 stroke motorbikes, I learnt if you use premix you have to increase the jet size, to accomodate the oil, otherwise they will run lean, and so burn pistons, or seize up.

Having bought my small Tohatsu new, and seeing the instructions tell you to run 25 to 1 for running in, I can only assume this DOES NOT apply to these engines.

So run at 25 to 1, put up with a little more smoke, and the engine will be like new for years.

 

[dmayes]

The Mercury that you have is a detuned 3.3 and has a constrictor in the carb. You should not be using up spark plugs that quickly, are they soot blackened or are they white and burn't at the end? Your engine has a mixture control for tickover and it also has a rough mixture control using different notches in the needle at the top and a circlip to hold it in place which fits into the notches, this means it can be moved up or down dependant on which notch you use. If it has been assembled wrong you may be running on the wrong mixture and damaging the plugs.

 

[Joe_Cole]

I run both my engines (3.3 & 8hp Mariners) on 100:1. They are now 5 years old and still going fine, but it looks as if I am in a minority of one.
Time will tell if I am shortening their life; I'll let you know in 2010!

FWIW I suspect that marine engines generally expire from causes other than poor lubrication (i.e. corrosion, cooling, submersion). Only a suspicion; time will tell.