stranded-help

[jasondaves]

4 stroke yamaha 40hp. Ran fan coming up river, got back in boat after duck hunting for an hour and now it won't crank. Its getting gas, I don't know what the problem is.

[99yam40]

check your e/ overboard switch,
you would not be the 1 st to have it pop off on.
Dogs are usually the culprit that knocks it off

[jasondaves]

It's on so it's not that. This happened about a month ago and I let it sit for about an hour and it finally cranked. Its turning over good but sounds like its not getting gas but I know it is. I can prime the bulb until its tight and without turning the key the bulb will loosen after a minute or so.

[BaileysBoat]

I'm confused. Is the 40 cranking or not? What year & model is the 40?

Like 99yam says, with the safety lanyard pulled it will crank but not start.
Probably have an alarm as well.

[99yam40]

Good to hear you are not stranded like the thread title says, I thought you were sending something on your phone.
Give all the proper info on motor and what all you have checked so far.
Check to see if you are getting spark if it happens again, no way of telling if it is spark of fuel related until you rule something out.
Check fuel pump to make sure it is not leaking, but the primer bulb is just that a way to prime the fuel system. It has little plastic check valves that are not going to hold the pressure for long periods on time. Just my thoughts.

[jasondaves]

Made it back to the landing!!!!! And yes, we were stranded and I was using my phone to look at this forum. Me and a buddy went about 20 miles up in a WMA to duck hunt this morning. The motor (2010 4-stroke 40hp tiller model) cranked right up when putting it in the water this morning and ran great. When we got to our spot we turned off the motor and walked into a flooded area to hunt. When we came back to the boat an hour later it wouldn't crank. After running all the normal checks that's when I got on this forum etc. So we ran the *****ing motor for 2 hours to get us back to the landing. When we got within 2 miles of the landing I tried to crank the motor again and it cranked right up on the first turn and it ran great all the way back to the truck. Once back, I turned it on and off several times with no problems whatsoever. Then when I got home 20 minutes ago it wouldn't crank again. It's almost like it's flooding somehow. I just can't figure it out. This is the third time I've had this happen.

[99yam40]

So did you check to see if it was getting spark to the plugs when it does not start?

[jasondaves]

How do i tell if it's getting a spark? Do I simply pull off the plastic plug connected to the spark plug and see if i can see a spark?

[99yam40]

yes but you may get a shock if jumps to you. and I am not sure how good it is for the coil if it does not have a place to jump to, it may jump between the winding
Best to use a spark tester, you can find them at auto part stores or online.
or even a timing light will indicate if there is spark when attached to the plug wire without even pulling the wire off the plug

Should be still under warranty take it in and see what they can find

[dorf]

This may sound sort of basic to you... BUT... I've got a 2006, 50 2 stroke, always had/have problems starting. It always rotates but is reluctant to fire and start.

This past summer I replaced the battery with one with 550 CCA. It made a world of difference in the starting sequence. (Old battery checked GOOD though-don't know the CCA of it.)

(But even now(new battery), after sitting for a week or so, it sometimes still diddles on initial start.)


It Always starts EXCELLENT after initial start. ???

Somewhere on this site it relates that Yamaha recommends at least a 380 CCA battery.

So for what it is worth....maybe your battery is inadequate.

Worth a try, huh ????

[jasondaves]

Well I think I have the problem narrowed down. I'm not sure what it's called but when you turn the key to the on position (Not all the way over to turn the motor over) you will hear a light noise for about 4 seconds which I believe is the electronic fuel pump sending fuel to the carburetor. Well whenever it will not crank I never hear the pump turning on. So I'm assuming the fuel pump is going bad. For some reason though it only does it after I've run the motor for a while. If I let it sit for a while it'll turn on again. Guess I'll have to get a new one.

[99yam40]

If it is a 2010 model then take it to a Yamaha shop for warranty work.
not sure what would keep the pump from running, a switch, or other things maybe
but could check to see if it is getting power and pulling current when not pumping to see if it is locking up or not getting the power or a ground that is needed

Warranty work is warranty work, let them figure it out

[rodbolt17]

post a full model number, the 2010 40 should be fuel injected.
also does it crank over and fail to start or does it fail to crank over?
and yes I would take it to a dealer and hope they can replicate it.
fuel pump is NOT cheap and its a pain to access.

[99yam40]

This happened about a month ago and I let it sit for about an hour and it finally cranked. Its turning over good but sounds like its not getting gas

Rodbolt he said it turns over

[rodbolt17]

he also said it sending fuel to the carb .
said, is the key word here.