4.3 Merc Wont run in idle

A

anderson4884

Cadet
Joined
Apr 25, 2010
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8
Ok, lets try this again properly. I have a 2003 Crownline 180BR with a 4.3 mercury s/n ow000645. It has 150 hours on it.

I just pulled it out of winter storage and went to start it up. It turns right over and starts with ease with some throttle but when i back the throttle off to low rpm's or neutral it will stall out.

Any help would be greatly appreciated. Thanks
 
Bondo

Bondo

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Apr 17, 2002
Messages
71,159
Re: 4.3 Merc Wont run in idle

Ayuh,... My 1st guess is the Carb has poo in the idle circuit....
You'll probably need a Rebuild Kit...
 
achris

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: 4.3 Merc Wont run in idle

Sounds like Bond-o got you pointing in the right direction....

Could you do me a favour? Could you wipe your hand under your engine at the front.... I'm looking for an oil leak. It may be very small at his point in time...

Thanks....
 
JustJason

JustJason

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Aug 27, 2007
Messages
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Re: 4.3 Merc Wont run in idle

A few more things would be to check the spark arrestor to make sure it's nice and clean... engines need air to go along with that fuel. If it's not TKS make sure the choke is closed when cold and opens when warm. And with any carb, see if it responds to an adjustment to it's idle mixture screws or not.
 
A

anderson4884

Cadet
Joined
Apr 25, 2010
Messages
8
Re: 4.3 Merc Wont run in idle

Before I decided to go ahead with the carb rebuild, I went ahead and put some new spark plugs in and threw some carb treatment in the gas tank. It will idle now but when i rev it up and take it back down to idle it stalls out. Do you still think its the carb?
 
B

backyard mechanic

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Jan 6, 2009
Messages
203
Re: 4.3 Merc Wont run in idle

I know... I know... the whole thing about ethanol is over played too much but then you really should be looking for ethanol issues. Sure, dirt can do the trick too but if the carb sat with ethanol in it you very well could have contamination from the ethanol. Ethanol related failure of gaskets, O-rings and floats is more common on the older models but you're better to look at a cause for failure than not and have failure on the water. :cool:
 
justchange

justchange

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Messages
214
Re: 4.3 Merc Wont run in idle

backyard mechanic said:
I know... I know... the whole thing about ethanol is over played too much but then you really should be looking for ethanol issues. Sure, dirt can do the trick too but if the carb sat with ethanol in it you very well could have contamination from the ethanol. Ethanol related failure of gaskets, O-rings and floats is more common on the older models but you're better to look at a cause for failure than not and have failure on the water. :cool:
Click to expand...


This is a definate truth. Ethanol can melt plastic floats. I use it in the Jeep in winter months and avoid it other than that. The boat got 1 tank of it to help clean out the fuel system. Now it gets regular with Sta-bil in every fill. The Sta-bil also cleans really well. ;) I'd take it out for a day with a top off of fuel and additive. See what happens. It's amazing how using something can fix problems.:D
 
A

anderson4884

Cadet
Joined
Apr 25, 2010
Messages
8
Re: 4.3 Merc Wont run in idle

Im a little confused on those last 2 posts. Are you saying to put a tank of e85 in?
 
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