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Need help, yamaha 15hp 4-stroke won't start after getting water in the gas line

J

jb0nez

New member
Let me preface by saying I'm not particularly mechanically inclined. I learned the hard way that for example I need to buy ethanol free gas.
I have a 15HP 2005 Yamaha 4 stroke on an 11-foot zodiac.

I live on the Windward side of Hawaii where it rains constantly during winter. Each summer I add the recommended fuel additive, something with "ring" in the name, run it out to the sandbar a few times a month. Winter comes and I make sure it's got lots of the additive, and go out and start it (in a trash can of water, another lesson I learned the hard way) every few months. This last time I kind of forgot about it, and about 4 months passed - with the gas from summer still in the tank. I started it and it started right up. Made sure the fuel pump was pissing, let it run for 15 minutes when it died on its own. It wouldn't restart. I checked the fuel lines to make sure it was getting gas, I got as far as the fuel pump (I think that's what it is, the small metal box on the rear with an "in" and an "out") and pulled the line off and pumped the pump on my fuel tank, it squirted gas out just fine so I figured the problem was farther up. My roommate came along and made the observation that the gasoline felt like it had water in it. Sure enough, it didn't feel or smell like pure gasoline.

I'm guessing my fuel tank is not humidity proof and the constant rains got water in the tank, and the motor ran fine on whatever gas was inside it until it hit that water-gas. So I dispposed of the bad gas, bought a new tank of ethanol free, hooked it up and open the line on the fuel pump again. Pumped and pumped until what was squirting out was gasoline. Put the line back on, gave it a few more pumps, and tried to start it. I figured if I cranked it enough times the old bad water-gas would eventually get pushed out the exhaust and it would draw the good gas in and start. After about ten minutes of cranking I gave up.

I'm thinking of trying some of that engine starter stuff you spray into the carb intake while I start it. Is that a bad idea? Of course I'm not even sure where the air intake is, when I looked at some diagrams a few years ago the best I could tell it was under a metal plate. so I wouldn't even know where to spray the stuff.

Other than that I'm out of ideas. The local boat shop are extortionists, I've NEVER taken it there and left without paying at least $600. But they're the only ones accessible to me where I live.

Please someone help me. Do I just need to crank it more? I know it can run fine, it ran like a champ for 20 minutes until it hit the bad gas.
 
drain the whole system carbs lines and tank pull the plugs and clean and dry them turn over about 10 to 20 times with plugs out to air out the cylinders make sure no water is sitting in the cylinders then add a little shot of gas to each cylinder reinstall clean plugs and try to start immediately
 
Thanks, great ideas ... pulling the plugs I can manage and putting a wee bit of gas into the cylinders I can manage. But the carb on this thing, even with schematics I can't tell where it is in order to drain it. There's nothing in there that looks like a car carb.
 
It's hard to get all the water out of a carb because it will sit in the bottom of the bowl, you will have to figure it out or take it to someone, I say figure it out.
 
I can't figure out where the carb bowl is. It seems the carb is buried inside a metal casing. It goes Black plastic air intake - metal contraption (carb presumably based on the fact the fuel lines and throttle all connect in some way to the metal contraption) - motor manifold(?). I've tried unscrewing the top of the metal contraption and all that's inside is a rubber piece the same size as the metal top and a few small holes and some odd grooves/channels in the metal. I think to get to the carb I have to maybe remove the black plastic air intake, then dissasemble the metal contraption. I'm not sure I'm comfortable with that.

But I have a question - I've been reading up on this Deep Creep stuff from Seafoam. Seems it claims to de-moisturize in addition to decarbonizing. I'm thinking what if I spray Deep Creep into the black plastic air intake while cranking the engine? Or what about removing the spark plugs and putting a bit of Deep Creep right into the two cylinders? BTW if if it's sunny tomorrow I'm going to borrow a socket and pull the spark plugs and just let the cylinders air out and hopefully any water in them will evaporate. I'm hoping water didn't make it that far because I've just learned that having water in the cylinders and cranking the engine can ruin the pistons since water is not compressible, and I've cranked it many times with the new gas. But to be safe like I said I'm going to air them out (and wire brush the spark plugs). If I do spray Deep Creep in while cranking, do I need to remove the plastic air intake and spray directly into the metal contraption? Or is it oik to spray Deep Creep into the black plastic air intake?

BTW I've always used "Yamaha Ring Cleaner plus Fuel Additive" and ethanol free gas. It's just that I live in a really rainy area of Hawaii, and I guess the gas tank is not airtight. I'm afraid the new gas I filled up with a month ago may already have water in it, we've had monsoon type rains.
 
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Ok I found the carb drain bolt, opened it up and drained the carb. Nothing but gas came out. I'm off to the hardware store now to find a socket that will get the spark plugs out and see what they look like.
 
I finally found a socket at Sears that would fit the spark plugs, pullled em out, wiped em down, wire brushed em, sprayed a bit of deep creep into the cylinders. Let it sit in the sun for a few hours, put the plugs back in, and it actually started!!! Blew off some white smoke first then died, had to crank about ten times to get it going again. Also I'm having to give it extra gas to idle, it dies if it's on the lowest gas. So before I take 'er out on the bay I'm going to take it in for a tuneup. I'm so proud I got it going again!!! This is my first foray into doing anything like this and to have it WORK is OMG amazing.
 
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