Mercury 15hp fuel not presurising please help!

Ok I am new to the forum and I have a couple of questions. I have a 2002 Mercury 15hp short shaft two stroke. When i bought it, it was really hard to start it would fire up second pull then stall then it was 15 or so pulls until it got going.

I put it in for a full service and told when I picked it up it had a little bit of water in the fuel which may have been the problem.

So last week I go to take it out, it still has the same starting problem. But now when it gets going it will only go to 1/4 throttle and it dies. I then went to feel the bulb and its soft and wont pump up hard? I changed fuel lines and fuel tank and no difference.

took it back to the boat bloke last week and spoke to him today said it has got him stumped, he said he is replacing the diaphram in the fuel pump but it looks ok though. So can someone help? I said to him how is it that it didn't have the problem before service and now after I pay my couple of hundred for a service its stuffed? He said wouldn't have anything to do with the service, I say rubbish.

Please help

Cheers
Jase

Re: Mercury 15hp fuel not presurising please help!

The bulb has a check valve in it (that's why there is an arrow). Sounds like it is stuck open.

Re: Mercury 15hp fuel not presurising please help!

I had this same issue with a Attwood bulb that was brand new.After i rebuilt my fuel pump thought.So at the ramp i proceed to take apart my fuel pump in about 90 noon sun.Just knew i put the check valves in backwards...Long story short i dropped a check valve in the water had to drive60 miles and spend 50 extra bucks to replace a new 5$ primer bulb.If it was me i would tell that guy to start there and take it off the hundred bucks he owes you lol.SAve your money and do the fuel pump yourself there simple.Just dont do it at the ramp in the water.....

Re: Mercury 15hp fuel not presurising please help!

Thanks for the replies guys but no its not the bulb, as stated I swapped my tank and fuel line with a mates who has exactly the same motor and it was still doing the same thing. His tank and fuel line work fine on his motor and my tank and fuel line also worked fine on his motor but not mine so its somewhere in the fuel system.

Cheers
Jase

Re: Mercury 15hp fuel not presurising please help!

Either the fuel pump diaphram fas a hole in it ot the inlet is leaking, they are both in the carb so get a kit and rebuild the carb.

Re: Mercury 15hp fuel not presurising please help!

Thanks for that laddies, the boat bloke is going to replace the diaphram so will see if that fixes the problem.

Cheers
Jase

Re: Mercury 15hp fuel not presurising please help!

This is very simple, the water in the fuel has gummed up the carb(or varnish) and the needle is stuck open, so fuel passes through although float is up...but motor won't run due to jets being gummed also....best guess.

Re: Mercury 15hp fuel not presurising please help!

3 months ago I changed the fuel filter on my Nissan 18 and afterwards the bulb would not fill no mater how many times I pumped it. I could see fuel in the pump and the filter and I ran it on the lake just fine over the next couple of months.

Before I put it away for the winter I changed the oil, filters, impeller and greese. Low an behold the bulb pumped up fine. As a test, I put the other fuel filter in and the bulb went back to being a problem again.

In my case it was definitely a defective fuel filter. I'm guessing theres a check valve in my filter also.