Anyone?

blocked fuel line perhaps. i think it has something to do with fuel anyway. maybe water in it. breather on the tank... spark plugs black though??? to much oil in the mix or getting injected??? 

I have a merc 90hp (04) and had similar problems. 

Got it serviced and they put the wrong plugs in.

Check they are the correct part number.

Good luck :)

It sounds like it is over oiling.  Is it a oil reservoir system or do you mix the fuel in the tank? Generally if it is oiling correctly and burning efficiently the plug ends should be almost like a hay or straw color.  If its oil reservoir they have been known to fail and the easy way to test it is disconnect the reservoir and mix the correct ratio in the tank.  Fire it up and see how it goes.  If you are losing pressure in the fuel pump bulb it may be that there is a pin hole in the fuel line somewhere, you may be able to cut an inch off the fuel line at both ends and an inch off each side in the middle where it goes into the fuel bulb.  Then reconnect and use the old clips or buy new jubilee clips to put it all back together. Connect it up and see if the bulb will hold its prime and stay hard.  Or you can buy a new fuel hose, connectors and bulb for around 25$ from Whitworths if you want to avoid any future issues because the hose may be degrading from sun damage/old etc.

check your fuel lines dont have a pin hole in them! this will cause it to suck down the level in the fuel filter! i would be also checking the choke is not sticking on!

Had a similar problem with my yamy 50. Definately sounds like a fuel obstruction. Mine turned out to be a load of bad fuel from the bottom of the tanks from the local servo that filled the filter and carby's with crap. Had the carbies cleaned and dropped and replaced the filter. Was amazed at the amount of crap that came out. Problem fixed after that. Cost me a lazy 300 to have the carbies cleaned though. Now I fill into jerries with a filter before filtering the fuel again as it goes into the boat. Bit of a pain but at least I now its clean fuel going in. Hope you get it sorted mate.

IMHO your motor is flooding not starved - why? ..... new boat, so you haven't learned the quirks of starting your motor yet....wet plugs, only wet thing in the cylinder is petrol, or maybe oil if the motor is stuffed, but well stuffed to pump oil into the cylinders then, so I think it is wet with fuel...... black plugs...flooding causes the carbon in your motor to loosen up and causes a residue of thick black wet shit on your plug - smell the plug as you take it out...petrol or oil? or carbon and petrol?.... Check the choke like was mentioned above and check your fuel pump and maybe your carb - needle and seat could be blocked open, and you are pumping heaps of fuel into your cylinder...on a 2 stroke, see if black fuel is running out of your exhaust, maybe down your motor leg---sure sign of way too much fuel...

I have a 25 Johnson, and the day I bought it I could not get it started back at home again - took it back, and the dude showed me the choke has a slow return on it to shut off as the motor warmed up, but needed to be pushed back fully to click into the off position to come off choke - this worked... after bloody hands trying to start the motor all morning, and heaps of frustration...

Try this.. connect the fuel hose on, try start the motor with the choke on - only crank 3 times for about 10 seconds each - if it does not start, make sure the choke is off, disconnect the fuel hose and give it 3 more tries for 10 seconds.. if it tries to fire with the hose off, then follow the flooding route of repair.

If it does not fire at all, take the cover off the motor, disconnect a plug lead, put a good plug into the lead, hold it with a rag against any earthed engine part, and have a mate crank the motor - see if there is spark on the plug - repeat with all plug wires... if there is good spark move along... no spark, find that problem.... could be weak batteries... as you crank, all the power goes to the starter and none left to generate a good spark... or loose wires....

Seems nothing serious though, as when you replace the wet, flooded plugs, the motor starts...

If you know the previous owner, just give him a ring and ask him how he did it after a bit of standing..

Good luck bro..

Let us know how you go..

 Hey Guys,

Thanks so much for all the advice it is greatly appreciated. I am happy to say I got the motor running but a bit embarrased to say it was mostly due to my ignorance of outboards that I couldn't get it started (being my first boat).

Firstly I was under the impression that the fast idle lever was actually the choke (Stupid I know) and didn't realise the whole push key to choke. I think what was happening is that when I was trying to start it I didn't have that fast idle lever pushed far enough forward and the butterflies on the carby weren't opening hence little to no air was getting into the cylinder which I as far as I can tell explains the over fuelling and wet spark plugs. When my mate was holding the throttle slightly open at the outboard end it started after 5 or 10 seconds.

Secondly I think I had a bit of a block in the fuel line somewhere. The little manual fuel pump seemed to always be half full of air so I took it all apart and reconnected it and now it fills completely with air and goes firm when squeezed a few times. I also changed the zip ties that were connecting the pump to the pipes with metal ones as the zip ties seemed a bit loose so I wanted to rule out air getting into the system at that point.

I'm hoping that it was just a combination of small problems and my lack of knowledge that was the problem as I managed to have it running fine in the driveway yesterday.

Sorry if I wasted anyones time it just gets a bit frustrating when you buy your first boat and can't get it started. Now I can go have a fish.

Thanks again for your help guys