Well, I've had my mercury 125 for 10yrs now. Come to find out I've not been starting the engine correctly. I use to prime the bulb til it firmed up then jam the throttle forward a few times and hit the ignition key while jockeying the throttle forward/back a few times in neutral mode til it fired up. Over time it was getting more difficult to start. I finally went online and found the correct way to start a Mercury. 1) Prime bulb 2) Trim engine vertical 3) Move throttle forward once to full position then back to fast idle/neutral position. 4) push in key to activate choke and turn key........Damn if it doesn't start on first try every time now. Boy do I feel like a dumb@$$.

I have the same motor, same problems so i am going to try your suggestion. I havent be pushing throttle foward and coming back.

so, all this time you were never told to push in the key giving a lil "choke" ??

you shouldn't need to more the lever forward. just push in key to choke it.

As Steve said above , Moveing the throttle forward and back should not and probaly won;t help a bit, None of the mercury;s i;ve had has a pump in the carb's, So moveing throttle does nothing at that point,

yes i press in the key to choke My current issue is getting it to initally start then wariming up is a biatch. once warm im good.. I usually have to press in the side switch on the throttle and use it to give more fuel to start and quickly to help it start.

on that 125 its the ole 2+2 motor so when you pump the throttle it will give the 2 cyls it doesnt idle on a small squirt of fuel on cold startup

Best way to start this engine cold is push in the nuetral botton in and move thottle till you just feel tention turn key to the on position and push in on key and count to ten then crank once engine pops off open thottle a bit and while it is running bump the choke till it smoothes out. Opening the thottle on a cold engine does not help because engine has no vaccum to pull the fuel up the idle tubes so just crack the thottle or just leave it closed till it starts.....OPTI

I didn't apply the choke properly before. Since I started using this new way to crank my motor it usually fires up way faster than before. It may take a few trys, but it works. I use to have to crank forever and hope she fired up. My step-dad taught me the wrong way to start a Merc. Back in the 80's he had twin 200 Black Max Merc's on his 23ft boat. They were hard to start and he use to start them by jockeying the throttle back/forth while cranking the engines. Old habits die hard I guess.

Yes some of the Mercs had accelerator pumps on the carbs back then and yes the 90,115 and 125 Merc has an accelerator pump. Main thing on this motor is to watch or be shure to change out the clear oil lines from the oil tank. If one breaks you will be running without oil and no warning untill the oil tank gets low enough for the float alarm to work. Have rebuilt several because of this.

Gary i have hijacked this thread but i need to ask what do i check for on that oil line, do i need to go ahead and change it out or what do i look for?