Reaching the end of my tether with outboards...non-runner...

[Max...]

Thanks guys, appreciate the replies, offline all yesterday but will read through all the points and come back, did try without choke and then with but if it was flooded it would have cleared in starting with throttle anyway as is normal to clear a flooded engine. I re-started it this way and ran about 10 times fine but just totally refused to run/start on idle regardless. Also went through all usual checks for loose wires/plug leads etc at the time but will check all over again.

[Fenlander]

Sorry to hear of this latest outboard trouble Max. My Mariner 15 wasn't usually run dry and I never used stabiliser and it would also start fine... even on fuel more than 6 months old.

What would be very telling would be to pop it in the tank then try and start as you normally would say with about 10 pulls. Then pull the plugs and see if they are wet with fuel or dry. Not sure that's been mentioned because I've skim read this, sorry if it has.

[Fenlander]

Sorry meant to say "it would always start fine".

Worth adding that my outboard experience of the past has covered mid 80s Mariner 2.5, 4, 8, 20 & 25hp... mid 80s Suzuki 3.5 & 8, 2001 Mariner 15 and of course 2006 Tohatsu 9.8. I'm excluding Seagulls as they are something of an oddity.

Most of these have been owned during the past 8yrs so many already 20-25yrs old.

None of them were normally run dry, fuel was from a variety of brands and stabiliser never used. Yet they would all start within a few pulls, often first pull even after 6mths+ plus over the winter of garage storage.

I know that doesn't help much but it's what I regard as the norm for a 10-30yr old 2-stroke.

[Max...]

OK, had another session this afternoon - no change.

Checked all electrics - I really cannot stress how mint and well maintained this engine appears, seriously looks like it was assembled yesterday, electrics connector/bullets/terminals are completely like new, clean and tight.

Plugs less than 10 hrs old, clean and gapped perfectly.

Spark on each on is good and strong.

Kill switch works perfectly as intended.

Looks like I'll have the take the carb off..

I wish one of you outboard guru's lived locally!

I ****ing *hate* the things....

[Fenlander]

Did you pop the plugs out in its no start condition?

[PeterM]

Still think the idle jet is not happy in the carb.....Giving you a screwed mixture at idle.

That's be my first look if it were mine.... But i could be wrong.. I often am really

[Max...]

(David, yes - plugs A1).

OK, carb off - and this little blue fellow that the primer lever acts on was all gummed up and stuck partially down, when I pushed it down it stayed...

[PeterM]

A common fault on those merc engines I've found.. Woop the four screws out (care not to lose the little spring in there) free it up put it back together and try again. Easy to do without taking carb apart...

[Locozodiac]

Max,

Check to see if you have a gummed up carb butterfly axis too, closes when pulling choke out, will not open fully when choke's back in. Clean with carb spray and lube with thin oil.

Happy Boating

[Fenlander]

>>>(David, yes - plugs A1).

Ah well yes.... but wet or dry.. big difference in what you're looking to find.

[beerbelly]

im thinking of swapping my heavy 2002 Yamaha 25 for one of these am I doing the right thing the yam just runs faultlessly all the time im having second thoughts now

[paintman]

If it ain't broke......

[The Gurnard]

Originally Posted by beerbelly

im thinking of swapping my heavy 2002 Yamaha 25 for one of these am I doing the right thing the yam just runs faultlessly all the time im having second thoughts now

A gunked up carb can happen to any outboard. I have 2 x 2006 two stroke Mariners..one is a 3.3hp and one a 25hp.. I run dry every time I flush them and they start no problem at all. The 3.3 has been in the family since new but I have only had the 25HP for two seasons however I am very happy with it.

I also had a brand new Tohatsu 4hp four stroke a couple of years back and although it was an ok outboard..it was a pig to start and flooded easily. I passed it on.

Give me the reliability of the two stroke any day..but Im sure everyone has their own favourite brand of engines and there is also a pig in everyone's life

Hope you get yours going again Max

[beerbelly]

the guy also tells me its normal for a 2005 mercury 15 that there isn't always water coming from the telltale this is new to me as all my previous outboards have pee,d constantly as does my Yamaha advice would be apreciated

[The Gurnard]

Its normal for my 25HP mariner not to pee water until it is up to running temperature.. the thermostat is the cause of this..so I think he is correct ?

however mine pees constant once it is warmed up..perhaps a couple of minutes after starting from cold.

Its easy to change the thermostat if it is a bit old or rusted..think it was only around 20-30 quid for a new one and gasket.

I changed both thermostat and impeller when I got mine second hand, as I didn't know its history..would do the same with any second hand outboard..its not difficult to do on a Mariner 2 stroke

[beerbelly]

thanks that's basically what he said once warm it pee,s fairly constantly ill have to see it running.cheers

[Max...]

Beerbelly - Perfectly normal with the Mariner as noted above due to 'stat.

Better the devil you know but all engines have issues regardless of make.

Anyway, to finish off the post earlier this evening with the pic, once I had the carb off I blew through all the orifices and jets and cleaned up the gunky plunger so it moved freely again.

And...bingo! It started on idle once more. Not sure what the plunger thing actually does but something to do with flow from the float bowl?!? I'm pretty sure that was the issue rather than a blocked jet?

However, on disassembling I mistakenly moved the mixture screw setting so need a little more help!

Can anyone give me a layman's guide/ballpark to setting this mixture screw correctly on the Mariner and an idle setting as all the workshop manual figures are for an engine in gear on the water...?

And I did not note which way up the float should go in the bowl. One side has a slightly raised concentric ring that I guessed should go against the brass float pin thingy rather than against the base of the bowl?

[A1an]

A rough guide is anywhere from a 1 1/4 to 1 1/2 turns out from lightly seated for mixture screw.

Idle screw is a suck it and see.

[bingosucks]

twas the carbs then great result well done chaps ,hoping for a similar result myself you really need to get a vacuum gauge on to set them correctly , i can reccomend windsor marine services this guy knows carbs

[uncle al]

Max that is the acceleration pump