How to change Mariner from starting off on 2 cyl.s
As I understand it , this 1993 115 hp. Mariner 4cyl will start off on 2 cyl.s till it hits 1800 rpm and then go to all 4 cyl.s Is there a way to eliminate the starting off on 2 cyl.s ? Thanx for the input . Cooter
Re: How to change Mariner from starting off on 2 cyl.s
This is handled by a pretty enginious mechanical system, based on pressure in fuelsystem. It is not simple to disconnect, but ofcourse you can run hoses by it and have a constant feed to all four carburettors. I fear it may take some modification to the carbs as well as only the two upper ones are designed to work in idle.BTW: Why would you wanna change it?
Re: How to change Mariner from starting off on 2 cyl.s
I am not sure why. But I have not run it yet , this motor has been sitting for 4 years and has approx. 75 hours on it , so its like new , but I am doing all this stuff like rebuilds on all carbs and water pump ,fuel lines , trim & tilt ,and now the stator . Any way friends of mine bought it new in 1993 and they parked it when it started not running right . So I thought maybe the reason for not running right could be this 2 cyl. thing . I don't know anything about this 2 cyl. thing . Thanx Cooter
Re: How to change Mariner from starting off on 2 cyl.s
The operation of the 2+2 system is actually quite simple. The bottom carbs provide only enough fuel for lubrication, but not combustion until 1800-2200RPM. At that point, the throttle butterflys open the passages in the carbs that allow more fuel to flow and allow combustion for operation on 4 cylinders. Modification to idle on 4 cylinders would be difficult considering the engine is designed to idle on 2. Hope this info helps!
Re: How to change Mariner from starting off on 2 cyl.s
I have a 98 model 115 Mariner, i am finding out now that it idles on 2 cylinders. It runs rough on these two cylinders and a carb job didn't help. I wish I had known this before buying it. It's the only thing on the boat I dislike.
Re: How to change Mariner from starting off on 2 cyl.s
Maybe there is still something wrong with yours , its hard to think that they would put these motors out for that many years if they idle so rough, people would not have kept buying them I would think. Let me know if you find out something about your idling. Thanx Cooter
Re: How to change Mariner from starting off on 2 cyl.s
My 115 Merc runs like a dream. Idles at < 1000 rpm all day long, never fouls a plug.A slight roughness can be detected the moment it changes to run on all 4, but it is amtter of seconds.I once found it rough running around 1200 rpm, but 4 new plugs solved that right away.This is yet another occasion to mention, that you need a manual if you want to DIY or just to know more.
Re: How to change Mariner from starting off on 2 cyl.s
What year model is yours . And I wonder if the owners manuel has more info on the running of it, than the repair manuel ? Thanx for your input . Cooter
Re: How to change Mariner from starting off on 2 cyl.s
Mine is ´91 but the 2+2 system is the same.Got a Seloc and a repair manual and find them both pretty good on the subject. Remember when you tune it, that only the two upper carbs have screws for idle adjustment. As little as 1/8 turn can mean a great difference.I've seen a couple of those motors running rough and too low idle due to too rich mix.
Re: How to change Mariner from starting off on 2 cyl.s
Getting these motors to run on 4 all the time is really simple. The bottom carbs don't have idle jets, the top 2 do. Just order 2 more top carbs (That have the jets) and replace the bottom carbs with top carbs.Craig
Re: How to change Mariner from starting off on 2 cyl.s
Yez, rebuilding it to 4 x top carbs would do. I still do not see any reason, though.On mine the 2+2 does xactly what it's meant to: Saves fuel, makes idle-running better. It idles and runs any rpm for any period of time with no problems. You don't notice any vibrating, uneven run or anything. Just smooth.Starts in idle both when cold (squeeze bulb till hard + 3 times, turn (press and hold) key), and warm (just turn key).If you could get yours running up to specs I'm sure you'd forget about converting it.
Re: How to change Mariner from starting off on 2 cyl.s
Mines not even on a boat yet , its been sitting for 4 years on a pontoon boat ( that I don't want or need ) so I might not can tell any difference between it or some others . I just did not like the sound of the 2 + 2 thing , but I guess if all is right then it will be ok. Thanx for all the input . I hope UU with the other one will get some adjustments to make his right. Cooter
How to change Mariner from starting off on 2 cyl.s
Linear Mode
