I have a 1999 125 merc. classic. my question is, when below 2000 rpm, does it run on only 2 of the 4 cylinders? and if so, is this an electrical shutoff, or a mechanical shutoff? <br /><br />thanks<br /><br />tim
In other words, the bottom 2 carbs don't have idle jets. It sucks enough fuel/oil to keep it lubed, but not enough to make power.<br /><br />I have heard of guys buying the #1 & #2 carbs and replacing #3 & #4 with them, then it would idle on all 4.<br /><br />Craig
thanks, does adding the 2 new carbs make much of a difference? ( smoother idle or acceleration), i do alot of low speed running and want to know if it wuold help that at all.<br /><br />thanks
The only real thing (That I have heard of) that it would get rid of is the surging at around 1800 - 2000 when the bottom 2 cylinders are just starting to come on line.<br /><br />This 2+2 motor is the reason I went with the older inline 6 Mercury. Just my personal feelings.<br /><br /> http://www.myfishingpictures.com/showphoto.php?photo=13002&sort=7&thecat=500&password= <br /><br />Criag
The idea behind the 2+2 is running on two cyls. below 1800 rpms is to permit trolling speeds with the bigger motor and better all around fuel economy. The key to getting these motors running good is carb sync. They tend to have a little more lope & vibration at idle as you would expect with that big of a motor running on 2 cyls. Decarbing the motor once a year helps. Also I use a full synthetic on my '97 125 and that seemed to help smooth the idle a bit and nearly eliminated the smoke. Do a search using the red search icon above for "2+2" and you'll find more info on these motors. You need to learn where the kick in point is and throttle accordingly. I have mine propped where you can't really feel when the second 2 cyls. fire up.
