Mariner 15hp 2 stroke frustration

Simon Guest · 14 February 2006, 20:10

Well, today was the first day out with my new Zodiac Classic Mk2C with Mariner 15 2 stroke. Pretty impressed with the boat, less so with the engine so far ...

The first 10 minutes or so were OK, but it did take too many attempts to get it started. Then when the engine was quite warm, it sounded like it was running too rich, and then stopped (right in front of the IoW ferry, oh dear, furious paddling required).

Following this, it was a real struggle to get it started again, and then when I put it in gear, it just died every time. Finally decided to give up.

My suspicion is this: having carefully followed the instructions in the manual regarding running in, I have twice as much 2 stroke oil as I should have. The manual says: 50:1 ratio in normal use, but 25:1 for the first tank. However, a sticker on the engine says 100:1 in normal use. I have 25:1 in the tank. Could this be the problem?

Any ideas?

BTW: I checked obvious things like: killcord, vent on the fuel tank, kinks in the fuel line.

cheers,
Simon

codprawn · 14 February 2006, 20:54

How new an engine is it? Many modern engines will cut out if there is no cooling water detected or an overheat.

Take the plugs out and have a look - if they are seriously fouled then that would cause probs.

Simon Guest · 14 February 2006, 21:12

Oh, it's a brand new engine, should have said.

There was a tell tale showing, though at tickover it's not much more than a dribble. With a few more revs it squirts out a bit more convincingly.

Poly · 14 February 2006, 21:42

When I first got my Yam 20 HP it was a bugger to start the first time. A mechanic who was with me at the time told me this was normal with new engines as they were quite "tight". Seems better now - after being broken in. Again this was running on "excess oil".

I think the problem with stalling when you change into gear is that it hasn't warmed up enough - you are presumably running the revs a wee bit fast at tick over? But in order to change gear you need to have the throttle closed (otherwise the gear shift is locked). If I remember rightly this was a problem for the first trip out but not now. You either need to be very quick at closing the fast idle, changing gear and putting on some throttle or wait till its hot.

Tell tale doesn't sound right though mine definitely has a constant smooth stream at tick over.

NEIL

Bigmuz7 · 14 February 2006, 22:07

Right, find a quiet bay round the corner, with a pair of oars and get used to your engine, run some tests, I've got a Mariner 10 that has been spotless. They do need warmed up. If you shut the choke too soon and then ask for throttle it will die. If it still dies when hot, then the carb needs adjusting .. so ...dealer problem when u have the warranty

codprawn · 14 February 2006, 22:59

Don't run at 100:1 either - the environment will love you - the engine won't!!!

phantom 19 · 15 February 2006, 00:08

Mercury/mariner 15 telltales are inconsitant until thermostat opened up.

Poly · 15 February 2006, 00:11

Quote:

Originally Posted by codprawn

Don't run at 100:1 either

Even if thats what the manual recommends? Its a new engine - surely if Mariner says it OK, then its OK - or they deal with the waranty claim? I know its common for people to run older engines oil rich - once things start to get worn - but are you suggesting ignoring the manufacturer for a good reason?

ADS · 15 February 2006, 00:30

jsut an idea but it sounds like its oiling up the plugs and or requires carb or idle adjustment. When mixing 25:1 I have always given the fuel can a good shake to mix it all up. If its running rich it will be smoky, and slow to pick up when you rev it. As Phantom 19 says I think the Mariners have thermostatic tell tales.
Its nothing to worry about just needs setting up and running in, best of luck with the new boat, might see you over the summer in the Christchurch / Bournemouth area.

Alex

Downhilldai · 15 February 2006, 01:02

I know you've mentioned that you've checked the tank vent, etc.
Are all the fittings and clips on the fuel line secure? Try squeezing the primer bulb when it's running to see if this 'cures' the problem - it could be drawing air into the fuel line, or possibly the fuel pump under the hood isn't doing its job?
This forum is really helpful for trying to solve problems like this, but more often than not, a look over the engine is the best way forward.
If you can't spot anything obvious, take a trip down to the local/supplying mariner dealer and ask them to take a look at it. That's what your warranty is all about, after all.
Good luck.

codprawn · 15 February 2006, 04:43

Quote:

Originally Posted by Polwart

Even if thats what the manual recommends? Its a new engine - surely if Mariner says it OK, then its OK - or they deal with the waranty claim? I know its common for people to run older engines oil rich - once things start to get worn - but are you suggesting ignoring the manufacturer for a good reason?

No he said the manual says 50:1 but a sticker on the engine says 100:1. Remember the manufacturers have all sorts of emmission regs etc to deal with. YES the engine will run on 100:1 but it will last a lot longer at 50:1

Hugh Jardon · 15 February 2006, 08:34

if the tell tail is a bit week and it cuts as it goes into gear and it is a new engine then perhaps the revs are just set too low, try raising the idle speed a bit so that you get a more steady stream from the tel tail and try that.

Simon Guest · 15 February 2006, 20:07

Thanks for all the helpful suggestions. Yes, I discovered that the tell tale is affected by the thermostat, which as it cuts in reduces the tell tale to just a dribble, ... until it cuts out again, and it spurts out nicely.

A quick visit to the local Mariner agent reassured me there was basically nothing wrong with the engine. I will take the advice of finding a quiet spot to get used to the engine - I think that's all it is. I was probably spoilt by turn-the-key 4 stroke electric start thingummy on my previous Mariner 60.

cheers,
Simon

PS: Still puzzled about the conflicting 50:1 to 100:1 oil ratios though. How can an official Mariner manual be wrong? How can an official Mariner sticker be wrong? Perhaps codprawn has the right hunch here ...

jwalker · 15 February 2006, 20:44

Quote:

Originally Posted by Simon Guest

...PS: Still puzzled about the conflicting 50:1 to 100:1 oil ratios though. How can an official Mariner manual be wrong? How can an official Mariner sticker be wrong? Perhaps codprawn has the right hunch here ...

I've no idea about your particular model but there was a time when the smaller Mariner outboards were actually Yamaha Origin engines rebadged. Mariner manuals said 50:1, Yamaha engine sticker said 100:1. A bit of extra insurance by Mariner. I was under the impression the Mariners are now Mercury motors.....it could be a similar thing or maybe you've got a Yam.

Poly · 15 February 2006, 20:48

Codprawn,

I am inclined to agree with you. I have been told many times that it doesn't do any harm to add extra oil.

However, Yamaha's marketting material (http://www.lake-link.com/yamaha/outboardbuyingtips.cfm) implies that 100:1 actually gives longer engine life...

100:1 Fuel:oil ratio:
Conventional 2-stroke outboards mix oil with gas for lubrication. Modern techniques have enabled quality manufacturers to produce engines with closer tolerances. Some manufacturers continue to produce older technology engines that typically use 50:1, or twice as much oil. The 100:1 ratio means less oil required (producing) less blue smoke, smoother running and an engine with a longer life. Be sure to use only Boating Industry Association (BIA) certified 2-cycle oil in your new outboard. Yamaha pioneered 100:1 fuel:oil ratio in 1984.

Perhaps 2-stroke engines would have a better reputation with both the boating community for being less smelly and the wider population for being less poluting if we actually operated them to the correct oil spec.

Just some thoughts...

codprawn · 15 February 2006, 23:24

Quote:

Originally Posted by Polwart

Codprawn,

I am inclined to agree with you. I have been told many times that it doesn't do any harm to add extra oil.

However, Yamaha's marketting material (http://www.lake-link.com/yamaha/outboardbuyingtips.cfm) implies that 100:1 actually gives longer engine life...

100:1 Fuel:oil ratio:
Conventional 2-stroke outboards mix oil with gas for lubrication. Modern techniques have enabled quality manufacturers to produce engines with closer tolerances. Some manufacturers continue to produce older technology engines that typically use 50:1, or twice as much oil. The 100:1 ratio means less oil required (producing) less blue smoke, smoother running and an engine with a longer life. Be sure to use only Boating Industry Association (BIA) certified 2-cycle oil in your new outboard. Yamaha pioneered 100:1 fuel:oil ratio in 1984.

Perhaps 2-stroke engines would have a better reputation with both the boating community for being less smelly and the wider population for being less poluting if we actually operated them to the correct oil spec.

Just some thoughts...

Granted there will be less fouling etc with 100:1 and for boats that cruise around at low speeds all the time 100:1 could well be better - however once you start cracking open the throttle all that carbon will be burnt away and you will need more oil. Just look at the mixes the racing boys use - often 25:1 50:1 is considered very daring!!!

tue · 17 February 2006, 19:00

We tend to recommend using 50:1 rather than 100:1. The internals haven't changed and they only introduced the 100:1 to pass the new EPA regs that came out a few years back. It makes it better for the environment, but the engine would benefit from the extra oil.

Not that it matters as Merc/Mariner are no longer producing 2 stroke engines anymore, unless DFI.

ps. With regard starting, I find 3 primes on the primer and wind it up to fast idle, then pull. When it fires push the primer back in. I can get them started first time every time with this method

Simon Guest · 17 February 2006, 20:31

So here's my final outcome: after listening to lots of good advice, and having another outing, I now understand what's happening. At 25:1, when running at tickover, the plugs are fouling up with the extra oil. By revving the engine, I can burn it off, and all is fine. However, if I let it run for more than a few minutes at tickover, it dies, and is a real struggle to get going again. The engine is just about useable as it is, but I have to be careful to keep the revs up.

Looking forward to the next tank of fuel when I won't have to be so careful with my revs ...

But for now, I'm thinking about another problem.

cheers,
Simon

Simon Guest · 13 March 2006, 21:56

... and having used half a tankful at 25:1, topped up and now on 50:1, ticks over nicely, confirming previous theories. Am planning to move onto 100:1 after another half a tank.

cheers,
Simon