How much more reliable are 4t Outboards than 2t

I have toyed with the idea of a 5hp 4str but after reading this thread concerning all the TLC you have to give the 4 strokes and the neglect I get away with, with my 20 + year old Yamaha 5, I'll stick with the old and tested
 
The main problem with two strokes is the petroil mix which is a) very sensitive and b) tends to gum up the carb and plug. I've had a Mariner 2str which caused no trouble with just a basic service every year, a Seagull which starts and runs fine as long as I remember to open the vent screw on the tank cap, and have currently got a Honda 2.3 which also runs well with the above proviso. I can't understand why the Honda is regularly slagged off on here (apart from the rusty fixings). I know several people with them and a quick scan of any dinghy pontoon shows their popularity. Unreliable equipment never becomes popular - word spreads.
I expect the Seagull, although already approaching 50, will be the only one still running in twenty years time.
 
reginaldon said:
I have toyed with the idea of a 5hp 4str but after reading this thread concerning all the TLC you have to give the 4 strokes and the neglect I get away with, with my 20 + year old Yamaha 5, I'll stick with the old and tested
Click to expand...

What? You have to lay it down a particular way? A yellow dot of paint on the uppermost side is easy enough for most to remember. Don't forget you don't any fart-arsing about with 2T oil and measures, remembering which can is treated, etc to bother about.
 
Lakesailor said:
What? You have to lay it down a particular way? A yellow dot of paint on the uppermost side is easy enough for most to remember. Don't forget you don't any fart-arsing about with 2T oil and measures, remembering which can is treated, etc to bother about.
Click to expand...

The trick to that is to fill a typical 5l can with 4.5l from a petrol pump and add the required amount of oil straight away. Voila - no untreated oil although the measure is a pain
 
jac said:
The trick to that is to fill a typical 5l can with 4.5l from a petrol pump and add the required amount of oil straight away. Voila - no untreated oil although the measure is a pain
Click to expand...

I have a 5l can on the boat; the simple rule is that it always contains 2-stroke, never unmixed petrol. I bought a load of 100ml plastic bottles a few years ago and decanted a bottle of oil into them, so one bottle tipped into the can makes 50:1. No faffing about with measuring.

Pete
 
Also retain 5l can on board and have got a 100ml graduated container for oil measuring. The challenge I have it that 5.1 l in a 5 l container is very full indeed which makes filling the OB tricky without an exxon valdez moment. Equally the 100ml container has minimal freeboard so again - pouring all of an almost brim full container of oil into the 5l can is a delicate art. - I find 90ml easy to measure - plenty of freeboard when then pouring the oil into the 5l can so no spillage and 4.6l in the can gives me plenty of room to shake the 2 stroke mix and pour without fear of a spill.
 
prv said:
I have a 5l can on the boat; the simple rule is that it always contains 2-stroke, never unmixed petrol. I bought a load of 100ml plastic bottles a few years ago and decanted a bottle of oil into them, so one bottle tipped into the can makes 50:1. No faffing about with measuring.

Pete
Click to expand...

That's a good idea, I think I'll copy that!
 
It's really interesting to hear the experiences with outboards.

In 1997 I purchased the new Honda 2hp with centrifugal clutch. I still have it and generally I have been horrible to it. It's never been
to a dealer, dunked twice ( once all night trapped under a pontoon) . I change the oil and plug and it runs as well as ever. I did renew the
throttle cable that finally rusted through this year.

My new to me Mariner 4hp 4 stroke is incredibly powerful when used on displacement boats. Starts beautifully and sips fuel. It did cut out a couple of times but got going again when I squeezed the bulb. I bought a new in line filter. This cured the problem. When I blew through the new filter it was much easier than the old one. I cut through the old one and it was as clear as a whistle ? Perhaps they break down after time.
 
I've just had to replace my Yamaha 9.9 4-stroke, the main engine on the boat. The boat log shows 36,000 miles and it's 15 years old. I reckon it ran for 3000 hours, and it just wore out. The compression was low, the valve guides worn, the shaft seal letting go, the prop ragged and thin, impeller and timing belt needed changing and the cooling channels weren't working as well as they should. It was all repairable, all spares available, but it was going to cost over £1k to fix everything, and for an old engine it wasn't worth it when £2k buys a new 10hp. In its life it always started instantly via the electric start (apart from one load of petrol from East Loch Tarbet which it objected to, as subsequently did my car), never had anything done other than oils, plugs, filters and grease. It had one spare in its life - a new diaphragm for the fuel lift pump.
 
Last edited:
I was a 2T fan - still like them. But as Lakesailor says the 4T's are so much more frugal on fuel. 2T's, contrary to popular legend, will not last forever. The 'simpler' technology relies on the integrity of the crankcase seal. Once that starts to go, then it becomes difficult to start and unreliable. Another common fault with age is noisy worn main bearings - which only get worse.

My 4T is a 2.5HP Tohatsu - yes, heavy, but so far very reliable, and loads of torque. And uses much much less fuel than a 2T.

There's no wrong or right choice - its personal preference. Personally I would rather have a newer engine that I can rely on than one that is over 10 years old.
 
Jelly can also form above the fuel tap(and outlet filter) in the tank in my Mercury 3.3 a good clean is sometimes necessary even if the tank is up ended at season's end!
Nice to have a 30 year old motor running perfectly again with only one impellor as a cost item all this time!
 
You must log in or register to reply here.

Share this page

Top