Force 120 Coughs out at low idle

[Namron]

Hi, Force 120 coughs out at low idle. I also have to lower the throttle to get it started, which raises rpm's high. When I go to idle it "coughs" loudly and abrubtly stops. When I put it in gear and take off, it runs great while cruising. It's frustrating at the launch, Thank you for any suggestions!

 

[wraenking]

Re: Force 120 Coughs out at low idle

well, my 98' 120 is being rebuilt right now, and in the beginning, those were my symptoms. it kept on getting harder and harder to start as i went. does your overheating alarm work, do you have a wter pressure gauge, and was it monitored? im no pro, but from my experience, these are things that i will be doing in the future to make sure i never have to rebuild again. if you can, do a compression chack. check your plugs to see if you have a mustardlt looking color on them. (water in cylander)<br /><br />let me know, since i a mvery interested to still find out how i ruined mine.

 

[Namron]

Re: Force 120 Coughs out at low idle

Hey thanks for the reply, Just heard from a friend, he said it might be "cold sneezing" and my idle and air might need some adjusting, he also said it didn't hurt anything by this sneezing. Hopefully that's what it is. Hope this helps!

 

[eurolarva]

Re: Force 120 Coughs out at low idle

when you start it and it starts to cough goose the choke once and see if you have any improvements. Chances are you have some gum or varnish in the idle circuits of the carb. If you dont use stabilizer in your gas you should start. Rebuilding carb and fuel pump can be done for under 50 bucks and also replace all fuel lines and clamps. If you have a compression tester you should check that and post the results here.

 

[WhiteHorse]

Re: Force 120 Coughs out at low idle

Yes, it does sound like one of those Mercury/Force 120 downhill compression things, although there are other things that could cause these symptons. I am very curious to know what the compression is.

 

[96force 75hp]

Re: Force 120 Coughs out at low idle

hey check your fuel pressure areas, the fuel pump may just need a new diaphram kit. Not getting fuel will afect how she runs. Then adj screw correct