2002 Mercury 125 Hard to Start

I have a 2002 Mercury 125HP SaltWater Series outboard one of those 2+2 models. The problem I'm having is that it is very hard to start .... when it is cold and even when it is warmed up and shut down for 20 minutes it turns over forever before it starts. I bought this motor from a gentleman in Baton Rouge LA. it had 180 Hrs.on it and had it shipped to Alberta Canada. Do you think that there might have to be some adjustment made to the carbs because of the difference in air ?? By the way I put in new plugs,filter and fuel line and bulb.
SailFin

Re: 2002 Mercury 125 Hard to Start

There are lots of possibilities and lots of possible guesses as to the cause of hard start. I would suggest that you do a few basic/systematic troubleshooting tests to help narrow down or eliminate some causes. This is usually more effective than randomly fixing/replacing parts until the problem goes away. After doing these tests and reporting back on what you find out, you will most likely get better informed guesses as to what the problem could be, some possible solutions, or what other tests you can do to narrow down the problem further.

Here are my initial suggestions:

1) Check compresson on all cylinders to see if it is satisfactory.

2) Check the spark with a spark tester while cranking the motor to see if the spark is satisfactory.

3) Squeeze the fuel bulb while cranking the motor to see if the motor responds favorably.

4) Spray some premix (oil:gas 1:50) into the carb throat while cranking the motor to see if the motor responds favorably.

Re: 2002 Mercury 125 Hard to Start

It is a fact the the Eastern sealevel is NOT the same as the Western sea level.

So much for facts, the difference isn't enough to make a jetting change.

Hard to start 2 + 2

Pump Primer

Raise the fast idle lever (or press the Neutral button and move throttle arm past the shift and slightly into the throttle range)

While holding the key IN to engage the enrichener, turn key to engage starter.

Release the key once the motor fires.

Not uncommon for the engine to make 3 or 4 turns to fire stone cold.