1975 Merc 500 No Low to Mid Idel stalling NEED HELP

[MADMERCOWNER]

Okay lets try this again. My 50 Hp Merc can't idle and the only way I can keep it running is to tap the choke. At full throttle she runs fine. But getting there is a chore. Have to keep tapping choke or she dies. After half throttle she's ok. I have changed the fuel lines-fuel pump- fresh gas and she's vented.Plugs and wires are new as well. Previous to this problem I had no power on the water but ran fine on the hose. So I started to replace some thing and problem was still there. So I bought some carbs on ebay and they looked like the where in great shape. Better then mine. So I put them on. Started the boat and she ran fine on the hose so I took her to the lake to give it a try and she was sluggish but she ideled fine and full throttle she ran good, so I way happy. So I take her home and decide to buy a can of carb cleaner/ gum out thinking this should make it run smoother. But after I sprayed the entire can into it thats when I was having the idel problem. Also when I would spray the cleaner into the top carb she would start to die until I stop spraying. Whitch is normal but in the bottom carb it did nothing at all. Just wondering if you think its the carbs or something else. Also can someone please tell me what does the stator do and could it also effect the ideling and spark. Can it cause a miss. I think the carbs need a rebuild. Also my compression is 130 to 140 across the 4 cylinders. Hope you have some ideas. Thanx

 

[forddiesel]

Re: 1975 Merc 500 No Low to Mid Idel stalling NEED HELP

Did you adjust the air fuel mixture screw in the water with the boat in forward gear slightly above idle. Make sure that both carbs are adjusted the same amount of turns, start from 1.5 turns from gentle seated and adjust from there. Also as soon as it dies in the water pop the spark plugs out and see what they look like. good luck.