2 stroke/4stroke outboards

I know we beat this up pretty good last week but I'd like to comment on what I see in Sea magazine. More 2 strokes** .. as in not less. I thought Yamaha only offered 8hp to 25hp in 2 stroke but now I see they have 2 strokes to 150hp** ..* all carbureated. Nissan (Tohatsu) or should I say Nissan/Mercury as Mercury owns Tohatsu now has 40 to 115hp all DFI engines. Mercury offers 40hp to 225 in their Optimax series and Suzuki finally offers a really light 2.5hp OB (29lbs(only 2lbs more than the tiny 2hp Honda (air cooled))). I hope Yamaha has'nt thrown out the tooling for their 2hp 2 stroke (22lbs). Those guys are really in demand used in Alaska. Anyway when I saw there was going to be a list of new OBs in Sea I was afraid I'd see the last of the breed but there seems to be a very small rebound*** .. good.
Something else I saw in the magazine that supprized me was the Philbrooks Boat Yard add presenting "single engine - twin prop conversions" installations as a speciality. I thought it would be too expensive to have much merrit but it seems to be alive and well too.

Eric Henning

My 26 year old 2 horse, 2 stroke, Mariner outboard is still running well. When it reaches a point, if ever, I can't fix it anymore, I will drive to Arizona and buy another 2 stroke, as they are outlawed in California by the enviro-wackos.

My 1 year old 3.5 4 stroke Mercury (tohatsu) has been a pain for about 6 months. I keep it mounted upright outside and am constantly cracking the fuel bowl to drain out small amounts of moisture. I think part of the problem is that it uses so little fuel it is getting old. It is home now, I am going to flush the fuel system and can, then locate and mix 100% gasoline with some Marine Stabil. Maybe this will help.

In contrast, the 4hp 4-stroke single-cylinder Yamaha ouboard we have on our Livingston will go for months without being run, depending on where we take the boat on weekend cruises. But it always starts right up even after sitting for long periods of time. We do use Stabil in the fuel, but we run it on regular unleaded that we buy at an auto service station. Other than the Stabil we don't use any fuel additives. We don't run the engine out of fuel at the end of a cruise when we've used it, although we do flush the engine with fresh water using the handy flush port for this. So the fuel that's in the engine sits in there for up to several months, but we've not ever had any problems with it. I'm always rather amazed when it fires right up after such long periods of disuse but so far so good......

Easy starting has a lot to do with the condition of the fuel and little to do with whether it is a 2 stroke or a 4 stroke. Stabiliser is unfortunately a fact of life if you have to leave your fuel unburned for more than a month at a time.
If weight was not an issue for the location of the engine, 4 strokes would make more sense, as they are clean and quiet.
So long as I am hanging an outboard on the transom of a small dinghy, weight will continue to be the biggest factor, so until they get the weigh/hp under control in the 4 stroke world, I will remain in the 2 stroke world.

Yeah, I'd love to put an 8 or 9 horse 4-stroke on our Livingston but our 36-plus year old teak swimstep just wouldn't take the weight.

To leave a 2 stroke for really long periods of time I use Bel-Ray synthetic motorcycle racing oil. Can't use it in auto mix*** .. it's too viscus** .. won't flow in the injectors. But for pre-mix it's bullet proof. At 50-1 leave it sit as long as you want and it will start right up. It's viscus enough to protect the bores against rust too. Cost's 55 to $60 a gallon** .. can't remember if it's availible in smaller amount. Suzuki makes the lightest 4 stroke dink engine (2.5hp-29lbs) unless one can handle the noisy air cooled* Honda. I may need to use that engine as I'm considering mounting the dink on davits and flushing an OB on a dinghy hanging on davits would be awkward at best. Could be an easy reach from the dock/float but how to run it? Slack off the bow line, pull in the stern and run it sideways?

Eric Henning


-- Edited by nomadwilly on Tuesday 1st of December 2009 11:39:57 PM

But for pre-mix it's bullet proof. At 50-1 leave it sit as long as you want and it will start right up.

The problem with gas is the alcohol demanded to pay off the farmers.

Unless you can really seal a fuel tank air tight , the moisture in the air will be absorbed by the ethanol , and your engine will not like it .

Most OB racers mix the gas oil before EACH race , as the oil does not help the octane rating , and the water does not add to the power.

Most folks in PC, CT simply use a OB mix for the weekend , then funnel it into the family car , and consider the 50-1 oil as top cylinder lubricant.

FF

Hi Fred,
Just an experience. I use pump gas. Now the only thing I use it in is my chain saw. I started using the Bell-Ray on my ultralight aircraft. There I ran cylinder head tempetures in excess of 400 degrees and the full synthetic high viscosity pre-mix lube oil was the best protection. For a water cooled engine it's a waste of money*** .. except that it never seems to go bad. I never put mix fuel in an automobile w a catalitic converter however my Sububrban has see a lot of mix fuel*** .. it has no cat.

Eric Henning