1979 mariner 25 hp carb adjustments ?

[Michael leblanc]

What is the proper way to adjust lean rich screw on my motor 6950022 its something like that can't see it good

 

[Michael leblanc]

Re: 1979 mariner 25 hp carb adjustments ?

????????help please!!!

 

[Mi duckdown]

Re: 1979 mariner 25 hp carb adjustments ?

Explain the problem you are having.

 

[Michael leblanc]

Re: 1979 mariner 25 hp carb adjustments ?

It's sneezing when idle I just don't know the right adjustments on screw and if I have to set this while it is in the water r can I do it with ear muffs

 

[Michael leblanc]

Re: 1979 mariner 25 hp carb adjustments ?

Dang ain't no body knows this answer ????!!!

 

[MH Hawker]

Re: 1979 mariner 25 hp carb adjustments ?

If its sneezing its to lean, these motors like to run rich at idle and you can adjust it close on muffs but it has to be fine tuned in use on a boat in the water. Back the mixture screw out till it stops sneezing

 

[Mi duckdown]

Re: 1979 mariner 25 hp carb adjustments ?

adjust idle in foward gear, in the water/lake.

 

[HarborRat]

Re: 1979 mariner 25 hp carb adjustments ?

Check how many turns out the screw is at now. It should probably be about 1.5 to 2 turns out from lightly seated. If you have to go out much more than that to stop the sneezing (if you can) you should clean the carb. Should be set at idle in gear in the water...but you can ballpark it with the muffs, just err on the rich side (out).

 

[Mi duckdown]

Re: 1979 mariner 25 hp carb adjustments ?

^ what Rat said

 

[Michael leblanc]

Re: 1979 mariner 25 hp carb adjustments ?

Lol ok thanks y'all I was in the wind for a while

 

[Michael leblanc]

Re: 1979 mariner 25 hp carb adjustments ?

Ok went run it today in the bayou I adjusted it and it stop sneezing but some times when it's at idle it sound like it skips then it stops doing it then it skips again and I ran it some more for like 15 minutes and I stopped and let it idle in forward and neutral and it's stop doing it I let it idle for 5 minutes and it stop doing it can anyone explain ?

 

[HarborRat]

Re: 1979 mariner 25 hp carb adjustments ?

Ok went run it today in the bayou I adjusted it and it stop sneezing but some times when it's at idle it sound like it skips then it stops doing it then it skips again and I ran it some more for like 15 minutes and I stopped and let it idle in forward and neutral and it's stop doing it I let it idle for 5 minutes and it stop doing it can anyone explain ?

Hey, it's 35 years old . It's probably still a little lean at idle (or you went too far and it's loading up--too rich...hard to say without hearing it), or it could be "normal". How does it run otherwise? I'd say turn out the adjuster another quarter turn and see what happens. If you want it "perfect" do a compression check to see if that's even possible and if ok clean the carbs. Don't ever expect that old egg beater to run like a Lexus.

How far out is that adjustment screw now?

 

[oldman570]

Re: 1979 mariner 25 hp carb adjustments ?

When doing the adjustments out on the idle mixture screw only go out until the motor idles at or near 650 rpm when in FWD gear, then give the screw another screwdriver width turn out. Then try the running to see if the motor goes when giving it the gas on the water. It needs to be set so that when you go from idle in gear to WOT that it picks up and dose not want to stall out or have a dead spot when accelerating. You might need to adjust the idle out a blade width more or so. After getting the motor set to where you think it is right , shut the motor down fairly quick and see what the plugs look like. They should be fairly clean of carbon and a light brown color tint, or darker, if the plugs are not new. JMO
Oldman570

 

[Michael leblanc]

Re: 1979 mariner 25 hp carb adjustments ?

I have to videos but idk how to post them they on my phone free it stop skipping it ran and idle like it was brand new I was just wondering y it did it then stop .....maybe my motor hadnt warmed up yet?

 

[oldman570]

Re: 1979 mariner 25 hp carb adjustments ?

Checking the burn of the plugs will tell if the carb is set on the rich or lean side. If they look to be running on the lean side, you need to open the setting another blade with at a time till the plugs get to a darker color, as a lean running motor can do damage to the motor. Plug color can be found here on the forum by doing a search for it if you are not sure what the colors are. JMO
Oldman570

 

[Michael leblanc]

Re: 1979 mariner 25 hp carb adjustments ?

Thanks

 

[Michael leblanc]

Re: 1979 mariner 25 hp carb adjustments ?

Ok should I adjust lean rich screw after motor done warmed up and should it be in forward or neutral ?

 

[oldman570]

Re: 1979 mariner 25 hp carb adjustments ?

The motor has to be warm in forward gear in the water and set the idle screw so the motor is running at or near 650 RPM.Setting on the rich side enough to keep a dead spot missing when going to WOT. This is where a driver blade width comes into play. Once set everything should be fine, and reading/checking the plugs burning will tell if the high speed jets and carbs are working correctly. JMO
Oldman570