Mercury 150 hp carb cold hard starting

[MarvI]

Hi All. I have a 2003 carburated 150 hp Mercury engine that is hard starting when it is cold. After getting started, it runs fine and starts again immediately. The problem just started and has happened twice. I have changed spark plugs and the fuel filter. The primer seems to be working fine. It is clear to me that it is not getting gas to run. I can manually prime it and it will run for a second or two but then it dies. Up until a day or so ago, it was starting and running fine with the same fuel so I don't think that the fuel quality is the issue. Any ideas on what I should try next???

 

[crem1]

Re: Mercury 150 hp carb cold hard starting

Sounds like it could be carburator issues, cleaning and a new carb kit might be in order

 

[MarvI]

Re: Mercury 150 hp carb cold hard starting

Thanks for the feedback. The carbs looked fine so I put a kit in the fuel pump ($12) and it seems to work fine.

 

[j_martin]

Re: Mercury 150 hp carb cold hard starting

You dodged a bullet. Fuel starvation is the #1 reason these big v6's blow a piston.

 

[mniver]

Re: Mercury 150 hp carb cold hard starting

Hey,

I've got a 2001 Mercury 150 hp carb that I bought new. It has always been cold natured and hard to start. I was at the point of thinking of selling it and getting a fuel injected engine simply because I was frustrated every time I had to start the engine cold.

I took the engine to a local Mercury mechanic to have the trigger replaced. I told the mechanic that the engine was very cold natured. He told me this trick, and it starts every time now, first or second time I turn the key.

1) Pump the bulb until it is completely firm.
2) Turn the key on; not to the start position but just to the on position and push the key in to engage the choke. Do not let the engine turn over. Hold the key in and therefore choke the engine for 20-30 seconds. Give it a full 20-30 seconds with the choke engaged.
3) Release the key to disengage the choke.
4) Turn the key to start.

My motor now starts on the first or second "bump" while starting. I no longer have to "grind and grind" to get it to start.

This may not be what you're experiencing, but this works for me..