Mercury EXPERTS???2001 125 4cyl

[jerryjerry05]

125 Ser OP325500 @ up.
4 carbs.
The top 2 have air screws with springs.Out 1 and 1/2
The bottom 2 have the screws no springs.I think they are screwed in all the way????
Should it have them?
It starts and runs.Idles crappy.
Good compression,good spark.Plugs burning right.
Once it gets going it seems to go above an idle.

ANY ideas???

 

[Jlawsen]

Re: Mercury EXPERTS???2001 125 4cyl

What you have is a 2+2 motor. It runs on 1&2 at idle by limiting the fuel on 3&4 to just enough to lubricate but not enough to cause combustion. If everything is good they run pretty smooth. The carb screws are correct, do not change them.

The system is really simple but a rough idle can be many things. The first question is if it's sneezing occasionally at idle or if the idle is irratic or undesireably high. Both of these problems can usually be fixed with a link & synch procedure. If that fails then you have to get deeper into it and you should get a Genuine Merc Shop Manual.

I could go into a lot of detail but at this point, it wouldn't make much sense to you.

 

[MasterMercury]

Re: Mercury EXPERTS???2001 125 4cyl

Hey
Just want to say he is correct on the 2+2,but for alittle advise. if you are setting up to 2 top carbs have your motor in the water, you need correct backpressure. only runs on top 2 cyl until fuel is sucked from the high speed jet when q throttle roughly. idle screws about 1 1/2 to 2 turns out... Anyways have to go watch stanley cup finals GO KINGS GO
Good Luck

 

[jerryjerry05]

Re: Mercury EXPERTS???2001 125 4cyl

Got the manual.
Try to enlighten!!Details?
Pretty quick study.
Haven't worked on many Mercs.I specialize in Force.

 

[Faztbullet]

Re: Mercury EXPERTS???2001 125 4cyl

Hey Jerry...If you got the manual do the sync and link in a barrel or lake...the bottom 2 screw are block offs.

 

[jerryjerry05]

Re: Mercury EXPERTS???2001 125 4cyl

Thanks Fast and Master,
It was running on the muffs.Just wondered about the no screws.Master wrote(put it in the water it needs backpressure)that helps.
Will put it in the water after reading the manual.
Thanks again,Jerry