Fuel pouring out near prop - won't start

[rlzsmith]

Hello. I have a 1985 Mercury 50hp 4 cylinder. It has always started great until I ran it out of fuel and didn't try to start it for several months. Now, I have cleaned the carbs and put in new spark plugs. The bulb feels good when I prime it. It is getting spark. New battery. But it won't fire. After cracking on it for 5-10 seconds, I noticed fuel is pouring out the bottom (exhaust?) at the prop.<br />The plugs are wet but not as much as I would expect.<br />Any suggestions?

 

[Vlad D Impeller]

Re: Fuel pouring out near prop - won't start

reset the carb float and make sure that the inlet needle is seating properly, engine may be flooding.

 

[Laddies]

Re: Fuel pouring out near prop - won't start

It sounds more like a bad fuel pump diaphragm to me---Bob

 

[rlzsmith]

Re: Fuel pouring out near prop - won't start

Sounds like you are suggesting I need to rebuild carbs.<br />Today I tested the compression, it is good.<br />Is there such a thing as a weak spark? I held the spark plug while cranking and it shocked me but not very strong. Could having a weak spark cause it to not fire (to flood)?

 

[Barnacle_Bill]

Re: Fuel pouring out near prop - won't start

You need to worry about that fuel problem first. A weak spark will not cause the motor to flood. With "pouring" out, I have to agree with Laddies. Rebuild the pump (kits are cheap) then if it still does it, rebuild the carbs with new needles and seats.

 

[rlzsmith]

Re: Fuel pouring out near prop - won't start

I have the carb kits ordered to rebuild integral fuel pumps and replace gaskets.<br /><br />In the dark tonight, I pulled one plug at a time. I grounded the threads and cranked it. It seems like the spark is coming intermittently.<br /><br />I'll let you know if the carb kit fixes it.<br /><br />Thanks!

 

[jheron]

Re: Fuel pouring out near prop - won't start

 

[rlzsmith]

Re: Fuel pouring out near prop - won't start

Hello again. I rebuilt the integral fuel pumps. That didn't seem to fix anything. Interesting though. Someone had rebuilt them previously and doubled up on diaphrams in one carb.<br />I checked the needle valve. It has a rubber tip. Looked fine. <br />It still won't hit a lick and there is gas dripping out at the prop after cranking.<br />Plugs are getting wet and there is spark.<br />Any thoughts?

 

[gss036]

Re: Fuel pouring out near prop - won't start

I think you are confused a bit, the fuel pump is seperate from the carbs. It is on the starboard side of the engine. Just follow the fuel lines. There are 4 small 1/4" bolts holding the thing together. If I remember correctly, the upper right and lower left hold it onto the block, loosen them and see if fuel is leaking/squirting when you prime the bulb. If so, remove it and install a rebuild kit. They are about $12 or so and not really complicated and come with good instructions.

 

[rlzsmith]

Re: Fuel pouring out near prop - won't start

Maybe I'm missing something. The fuel line comes into the front of the motor and goes right to the fuel filter on the port side. Comes out of the filter and goes straight to the carbs.

 

[rlzsmith]

Re: Fuel pouring out near prop - won't start

My serial number is A916774. It has twin WMA4 carbs.

 

[fishingdan]

Re: Fuel pouring out near prop - won't start

When you pump the bulb, does fuel leak out the front of any of the carbs?

 

[flips]

Re: Fuel pouring out near prop - won't start

That fuel filter you are talking about is a fuel pump.Pull it off and you will see A diaphragm and two check valves

 

[rlzsmith]

Re: Fuel pouring out near prop - won't start

The fuel filter I see is just a screw on plastic bowl with a filter element in it. It is just hanging on a bracket mounted to the block. The carburetors each have an integral fuel pump with a diaphram. This takes the place of the fuel pump.<br />I know I'm getting fuel past the carbs because it is dripping out at the prop after I crank on it for a while.

 

[rlzsmith]

Re: Fuel pouring out near prop - won't start

No fuel leaks out the front of the carbs when I pump the bulb.

 

[flips]

Re: Fuel pouring out near prop - won't start

When you cleaned out the carbs did you soak them and blow them out with air?.Did you check floatlevels ? did you adjust idle mixture screws.<br />have you got a manual if not get one for settings.<br />recheck float levels and needles and seats

 

[rlzsmith]

Re: Fuel pouring out near prop - won't start

It is running!<br />Checked spark again and it was getting spark. Noticed water in the fuel filter. Which by the way, there is no fuel pump on this motor. I verified with the Merc dealer. There is only the integral fuel pumps on the carbs which are diaphrams. Replaced fuel. Cleaned bowls. Noticed one carb had empty bowl. Reset float and that fixed it.<br />I decided it wasn't getting enough fuel in the motor so I opened the idle screws about two turns (already had them 1 1/2 out from closed). Then I opened the throttle. It started!<br />Then I tuned the carbs up nice.<br /><br />Thanks for the help. Hope this post helps somebody else.

 

[flips]

Re: Fuel pouring out near prop - won't start

Well done and good to see you posted to let all know the results cheers .