With regard to oily film....I would suggest the odd 'accidental' bilge water discharge, possibly has more to do with polluted water than what is emitted from a little 2 stroke 'mix master'.
After my ancient Seagull I bought a Honda 2HP 4 stroke which I thought was fantastic - always started first or second pull(unlike the seagull which always worked when tested but often failed in practice), NO oil, spilt petroil or smell in the car boot BUT I now find it heavier and sometines wish I had a small 2T like a Yamaha, Mariner or similar.......... Unfortunately all you can buy new nowadays in the 2-3HP range are all 4 strokes and the Honda still comes out tops(in my opinion) and it's still one of the lightest.
I have had my old Johnson 6 for 25 years and never had any problem with what you might call 2 stroke peculiarities. The Electronic ignition has failed once but you would get that on 4 strokes. The carby has gummed up that may be because of oil in the fuel but mostly problems have been in the cooling pump and pipes. Again you would get that with 4 strokes. So I don't think you can say 2 strokes are less reliable. Perhaps more depends on availability of parts and ease of dismantling. olewill
If you were comparing motorcycles of reputable manufacture, four strokes would definitely edge it in the long term. However, outboard engines don't wear out so much as succumb to abuse and neglect in a hostile enviroment.
Originally Posted by VO5
Pros: lighter; cheaper*; easier to resuscitate after a dunking; simpler; easier to service and rebuild.
Pros: usually quieter; slightly more environmentally friendly; take neat petrol rather than oil/fuel mix.
There are other factors, but this is the gist.
The oil film you somtimes see in the water is the marine equivalent of the smoke towed by a bloke on a 350LC having a lot of fun a couple of decades ago. There's oil in the fuel, so where else can it go?
The "*" is a biggy which may make your question hypothetical: for several years it's effectively been illegal to sell new small two-stroke outboards in the EU. There may be a few bits of old stock around which can legally be sold.
Two strokes have only fallen out of favour because of concerns over pollution. But many elderly people go boating and I can just about lift the 9.9 Evinrude 2 stroke off my transom, and the 4hp Mercury 4stroke I use for my tender weighs 27 kilo but a 4hp 2 stroke would weigh only 15kilo. Outboard motor-boating should be more user friendly.I want to buy a new 4hp 2 stroke so on my boat I have only 1 fuel on board.
Weight is a good point. I know there's lots of blurb about small 4-strokes getting lighter etc but the fact remains my 10hp 4-stroke is flippin heavy. I'm no sparrows kneecap but it's still a lump to get out of the well on the boat.
Originally Posted by Jim@sea
A couple more issues to consider too.
My 4 stroke has a single handle to help lift it and very few other lifting points. Its very smooth around the cowling.
Also 4-strokes generally (I don't know of an exception) can only be stored on one side. If you store it on the other or turn it upside-down, oil will flood the top-end and ultimately the floor.
I'd go for 2-stroke every time, lighter, easier to use, and probably as reliable as the 4-strokes. Going by an advert on E-bay it seems that you can only buy any old stock NEW 2-stroke motors if you are a commercial enterprise, daft really as most of our EU laws are. However, there are NO restrictions on second hand ones and that is where I'd look.
The OB engine I have currently is a 4HP Mariner which I bought second hand 4 years ago. I use it to push my Redcrest dinghy. I am very pleased with it. Its not thirsty, it starts without problems and keeps going until stopped.
The resaon why I started this thread is because on this site there is a wealth of expertise not found elswhere on the net and therefore one is more or less guaranteed to recieve sensible and informed replies and contributions for which I thank you all.
As this engine is a bit long in the tooth, although it is maintained and cared for, I was tempted to look at a replacement 4 stroke.
I am very grateful for your views because I now realise there is no need to do this. It seems 2 strokes are mechanically simpler, lighter and for this model there no shortage of parts. Also workshop manuals and parts lists are easy to get.
The slight oily discharge that worried me appears to have a simple straightforward explanation. It does not worry me anymore. I thought it was a fault as no one I have asked has been able to account for it.
I have made a sling for mine in an H shape. The H fits under the tank and the four corners have a ring each,. The sling is made of strong terelene tape and hand stitched.
A lifting lanyard with a shackle at the end that goes through all four rings is used to lift it on board and to lower it .
Ashore I have a horse. I made it out of 2 X 4 pine. Each side is an inverted V shape connected by a yoke upon which the engine is bolted when not in use.
The thing is held together with coach bolts in case it has to be dismantled, but even with its slightly splayed legs it fits in my locker at the club.
I left a clearance of 1/2" from the ground so that a bucket full of fresh water can be placed under it so the prop and inlet are submerged. Then I can run it at the end of the season to flush out any salt residue etc., works a treat !
Locally, we can buy a small wheeled trolley/hand truck to move and store outboards up to 25 h.p., quite cheaply. They appear a little cheap and flimsy, but mine has lasted several years and works well.
I liked your sling idea with the 4 hp. I have a 300mm (12") lanyard spliced to the carry handle of my 3.3 hp with a dog clip on one end. When locating onto the dinghy transom (while in the water), the clip is attached first, in case the engine drops into the water. It has come close a few times......
My vote would go for to the 2-stroke, been running a 3.5 Mariner as power for a clinker tender and an on-board inflatable, no complaints it's only 13k can be stored in nearly any plane, and takes little maintenace.
As mentioned you can still buy them 'as new' from a number of outboard stockists...just ask.
\a wise man said to me "smile and be happy things could be worse" so I smiled and was happy.....and things did get worse!!