15 hp Mercury 2 stroke won't run

[Philsboat]

[QUOTE=a64pilot;1937547]A way usually to confirm a faulty fuel pump is to pump the bulb, if it runs fine as long as the bulb is kept tight, that is a good indication of a faulty pump
Also you can squeeze the bulb when it is running.If it stalls the fuel pump diaphragm is perforated and letting fuel go straight into the base bypassing the carb.

[Lucky]

I think that all the various possibilities are listed above, apart from one which happens with my 15 hp Merc, or rather the fuel tank. I was out going to a boat shop to buy a part for my catamaran and the Merc started to play up and I had to choke and pump to keep it alive.
What happened was that the suction pipe inside the fuel tank had fallen off the top connection. Got the top fitting off and refixed the suction tube and all was back to normal.

Happy lead free sailing from Lucky

[pwmullins]

Thank you all for your kindly responses. I always use non ethanol gas and I run the gas out when I finish using it. No gas is left in the bowl. I will pull off the carburetor and blow out the Jets clean the bowl and check the fuel pump diaphragm. Thanks again.

[Cadence]

Originally Posted by pwmullins

Thank you all for your kindly responses. I always use non ethanol gas and I run the gas out when I finish using it. No gas is left in the bowl. I will pull off the carburetor and blow out the Jets clean the bowl and check the fuel pump diaphragm. Thanks again.

If you have done that you are ahead of the norm.. Diaphragm would be a good bet, it may have dried out and cracked? Post your find. Small OBs seem to be an ongoing problem.

[skipmac]

Originally Posted by pwmullins

Thank you all for your kindly responses. I always use non ethanol gas and I run the gas out when I finish using it. No gas is left in the bowl. I will pull off the carburetor and blow out the Jets clean the bowl and check the fuel pump diaphragm. Thanks again.

If that doesn't do it, try pulling the plug, reconnect the plug wire and hold the plug on a bare metal spot or bolt head on the block (using an insulated tool or piece of wood), have someone pull the cord and look to see if there's a spark in the plug gap. Should be a strong, blue spark. Weak or yellow spark it could be an electrical problem.

[Cadence]

Originally Posted by skipmac

If that doesn't do it, try pulling the plug, reconnect the plug wire and hold the plug on a bare metal spot or bolt head on the block (using an insulated tool or piece of wood), have someone pull the cord and look to see if there's a spark in the plug gap. Should be a strong, blue spark. Weak or yellow spark it could be an electrical problem.

Take a # 2 Phillips screwdriver put it in the spark plug cap. Hold the blade and a ground and get the wife to pull the cord.

[Nicholson58]

Originally Posted by Lepke

a64pilot is right. I have a similar Merc outboard and it clogs during layup if I don't add fuel stabilizer. It usually blows out with pressurized can of carb cleaner.

Add my name to the list. Sometimes I think the fuel evaporates and leaves the oil gunk behind - in the jets. I have been able to get them running with a lot of patience and babying it at low speed for a few minutes.

[jcapo]

Its got spark or it would not fire at all. Clean the carb.

[captain mitch]

I have had great luck re-activating old clogged up carbs and fuel injectors by loading the system with a super heavy dose of STABIL, (like a quadruple dose) and letting it sit for a few days. Then run it with again that heavy dosage of STABIL to clear it out.
My 2 stroke Merc gave me fits when I tried to run it on auto gas, non-ethanol makes it much happier even after storage.
BTW, same holds true for your Honda 2000

[Starblossom]

Hold your gas tank above your engine.
Start your engine. If it runs you have a problem between the tank and engine.
Most likely at the tank fitting
good luck
I had the same symptoms.
Try the easy things first

[skipmac]

Originally Posted by Cadence

Take a # 2 Phillips screwdriver put it in the spark plug cap. Hold the blade and a ground and get the wife to pull the cord.

Hey, be nice or you might get flooded.

There are some days that I think my wife would pull the cord.

[skipmac]

Originally Posted by jcapo

Its got spark or it would not fire at all. Clean the carb.

On my little Merc the spark became weak and intermittent and acted a lot like a fuel problem. In this case probably a long shot but it's really easy thing to check and you might get lucky and save overhauling the carb.

[waterman46]

Ethanol in gas attracts water. The more empty is the tank and the longer it sits, more water will show up in bottom of tank. Google "does ethanol in gas attract water". I learned the hard way, just like you.


Cheers,

[lsearite]

Originally Posted by a64pilot

I had to get home with my Mercury Verado big supercharged outboard by using the primer bulb once.

Got a 2002 Merc. Had same problem when first got it. Learned from friend to pull gas line off when close to docking and let it run out of gas.....everytime. took care of it. Mine sat in open for 5 months, started on 2nd pull.

[a64pilot]

Originally Posted by lsearite

Got a 2002 Merc. Had same problem when first got it. Learned from friend to pull gas line off when close to docking and let it run out of gas.....everytime. took care of it. Mine sat in open for 5 months, started on 2nd pull.

The new fuel injected motors are a little strange in how they work.
CG says no pressurized fuel lines in a boat, so therefore you can't do it like a car and just have a pump in the tank, On the Verado at least there is a tank on the back of the motor with two fuel pumps in it and a float switch. Think of it like the tank on a toilet. One pump is the high pressure fuel injection pump, the other pump is a low pressure pump whose job is to keep the tank filled, the float switch activates this low pressure pump just like a bilge pump, Ethanol eats up the float switch making it so the low pressure pump stays off, engine runs out of fuel.
Install a bulb in line (one is not installed with these high tech motors) and you can get home by pumping the tank full.

Then it gets even more interesting, the float is a ring on a stick so to speak that works I think by reed switches, anyway the float rides up and down on this stick and high RPM sets up a vibration harmonic that shakes the stick so the float rides up on the stick cutting off the fuel pump, and the engine runs out of fuel, loses RPM, harmonic changes and engine comes back to life.
The fix believe it or not was software that changed pump timing somehow or another.

Things are getting complicated aren't they