Setting idle speed on 3.0 merc

[Packers4ever]

I think my idle is a little high around 1000 is it easy to set or should I let a shop do it?<br /><br />Thanks for any help<br /><br />Skipper

 

[jeff13601]

Re: Setting idle speed on 3.0 merc

Do you have a single gas/air mixture screw?

 

[Packers4ever]

Re: Setting idle speed on 3.0 merc

I have not looked at the carb yet I just purchased the boat...sorry<br /><br />So I geuss what your saying is it's not just a matter of turning the idle screw down a little?<br /><br />Skipper

 

[jeff13601]

Re: Setting idle speed on 3.0 merc

It could be that simple, but you may have to adjust the air/gas a little. You should also adjust the idle in the water, in gear. Was the idle in the water in gear 1000 rpm's?

 

[Packers4ever]

Re: Setting idle speed on 3.0 merc

Im sorry I don't have the exact numbers for you I appriaciate the quick responses I'm pretty sure it does idle in and out of gear at around 1000 I think its a little lower in gear maybe 900 or so<br /><br />Skipper

 

[jeff13601]

Re: Setting idle speed on 3.0 merc

It should be down to around 600 or 650. I try to set mine on the muffs at 750

 

[Packers4ever]

Re: Setting idle speed on 3.0 merc

So I should do it in the water in gear then turn down the idle screw slowly?<br /><br />How do I know if I have to play with the air mixture screw?<br /><br />Skipper

 

[jeff13601]

Re: Setting idle speed on 3.0 merc

Turn it down a little and then turn the air adj screw back and forth a small amount and see if it reaches a higher, smoother rpm. Then you can drop the idle screw a little more. It should be done with a gauge but I have always just used my ear. If you are going to try it on your own keep track how far you have turned it in or out so you will be able to set it back if you make a mistake

 

[Packers4ever]

Re: Setting idle speed on 3.0 merc

Where is the air mixture screw will it be close to the idle screw?<br />Can I do it in the driveway with the muffs on it will work the same right?<br />Will I have to turn the idle screw quite a bit or very little?<br /><br />Thanks<br />Skipper

 

[jeff13601]

Re: Setting idle speed on 3.0 merc

I believe port side of the motor on the side of the carb. Give the idle screw a quarter turn out and let it run 30 seconds or so. If it needs more go another quarter

 

[Packers4ever]

Re: Setting idle speed on 3.0 merc

It idles at 900 when not in gear and 800 when in gear should I still try to lower it a little?<br /><br />Thanks JJR!!

 

[tommays]

Re: Setting idle speed on 3.0 merc

900 if correct is a real gear cruncher which is why they shoot for the 650 range<br /><br />tommays

 

[Packers4ever]

Re: Setting idle speed on 3.0 merc

Thanks Tommays!!<br /><br />When I put it in gear it does clunk pretty good I will attempt it tonight<br /><br />Thanks for the help!!<br /><br />Skipper

 

[Packers4ever]

Re: Setting idle speed on 3.0 merc

I attempted setting the idle and it almost stalled out so I turned it up a little and it was idling at around 700 which I was happy with when I took the boat out the next day it seems like it is idling at 900 again any ideas?<br /><br />Thanks for any help<br /><br />Skipper

 

[tommays]

Re: Setting idle speed on 3.0 merc

i have found that the controls dont return the carb to idle stop that well <br /><br />there should be a barrel on the cable (mines on the valve cover) that will allow you to remove it and give it a few turns so it pulls to the stop the same every time<br /><br />just a littel bit you dont want it mashing the stop just geting there <br /><br />tommays

 

[Don S]

Re: Setting idle speed on 3.0 merc

What year is your 3.0L?

 

[Packers4ever]

Re: Setting idle speed on 3.0 merc

Sorry for the delay guys!<br /><br />I have a 97 Bombardier Celebrity 180 so I am assuming it's a 97 Motor as well<br /><br />Tommays so what you mean is I am going to tighten the cable a little so it puts a little more back pressure right?<br /><br />Thanks Gents!!

 

[Don S]

Re: Setting idle speed on 3.0 merc

What you need to do is disconnect the throttle cable from the carb at (D), adjust the idle speed screw to the proper rpm, then reattach the cable. You will probably have to adjust the barrel (C) so the cable just holds a slight amount of preload on the carb to hold it in the idle position.<br /><br />

 

[Packers4ever]

Re: Setting idle speed on 3.0 merc

Thanks Don<br /><br />I will print this and try it when I get home! <br />Earlier someone mentioned an air mixture screw do you know anything about that?<br />Much appreciated<br /><br />Keith

 

[Packers4ever]

Re: Setting idle speed on 3.0 merc

Don?<br /><br />Do you know anything about the air mixture screw?<br /><br />Do I have to do this in the water idling or can I do it with the muffs on in the driveway?<br /><br />Thanks