50 horse Mercury hard starting

[TLanglitz]

I just got back from an unproductive morning of fishing .. (Is anyone in the St Louis area catching fish?) I told my buddy I'd mention this problem to the experts on this board. His 1979 50hp Mercury has suddenly become hard to start. This has always been an easy starting motor until today. Once we get it going it runs great both opened up, at a slow idle, and anything in between. If you hit the key immediately after shutting it off, it starts. If you wait a few minutes, you can plan on at least a few more minutes of cranking to get it to fire... and then it runs great again. It smells flooded when this happens, so I suspect it's a fuel problem. <br />What should I tell him to look for?<br />Thanks <br />Tom

 

[roscoe]

Re: 50 horse Mercury hard starting

Could be a worn out fuel pum diaphram, leaking fuel into the engine when it sits.<br /><br />They get old and deteriorate, only cost about $10, and takes about 30 minutes to put it in.

 

[TLanglitz]

Re: 50 horse Mercury hard starting

Thanks roscoe ... We'll check it out.<br />Tom

 

[rverano]

Re: 50 horse Mercury hard starting

Ditto on the fuel pump check. I had a motor that suddenly stopped running right. Replaced the fuel pump and it was fine. If the carbs have never been rebuilt, it might be time for new gaskets, and needle. I bought a small repair kit for $30. It's cheaper than a full rebuild kit and usually does the trick. A good cleaning of the carb helps alot.

 

[TLanglitz]

Re: 50 horse Mercury hard starting

Thanks rverano<br />I was told that the carbs were rebuilt less than a year ago. Thanks for the response though.<br />Tom

 

[andrewkafp]

Re: 50 horse Mercury hard starting

I don't think there is a problem with it. I have virtually the same motor and after I anchor for a while I have trouble knowing which starting technique to use.. Prime, choke, fast idle, or just turn the key. I usually get it wrong and try the choke, which floods it. Then leave it for a few minutes, push the fast idle up and it starts and a bit of dark grey fuel smoke comes out. I think this is normal for and old 2 cycle.