Motor Missing at Idle

[Fisherman_Wantabe]

I have a 1993 40HP Evinrude 2 stroke. It has started mis firing a good bit at idle. I put 2 new plugs in it yesterday, but still have the miss Any suggestions will be welcome I don't want to take it to the boat shop ($$$$) it I can fix it myself. It seems to run ok above idle. I have not put it in the water in about four months due to foot being broke.
I put Stabil (that may not be how you spell that) in it as soon as I could after breaking my leg in Nov 07.
Thanks for any help ya'll may have on this.

[Barnacle Bill]

Take it out and run it with some fresh fuel. It wouldn't hurt to add some Sea Foam to it. This is a great additive for cleaning out fuel systems and help getting rid of carbon build ups.

[reelcrappie]

I tink IBNFSHN hit on the head, sounds like your low speed jets are a little clogged, Sea Foam ought to do it. You might get a aerosol can of Sea Foam and spray it directly into the throat of you carbs.

[Fisherman_Wantabe]

Take it out and run it with some fresh fuel. It wouldn't hurt to add some Sea Foam to it. This is a great additive for cleaning out fuel systems and help getting rid of carbon build ups.

Were do you get Sea Foam I don't think I've ever seen any?? I guess the boat shop will have some, but it's about 40 miles away.

[Quicksilver1958]

Were do you get Sea Foam I don't think I've ever seen any?? I guess the boat shop will have some, but it's about 40 miles away.

O'Reilly's , Tractor Supply and Auto Zone carry Sea Foam.. Look in the carb and injector cleaner section.

[Barnacle Bill]

I tink IBNFSHN hit on the head, sounds like your low speed jets are a little clogged, Sea Foam ought to do it. You might get a aerosol can of Sea Foam and spray it directly into the throat of you carbs.

That stuff is made by Sea Foam and is called Deep Creep. It won't really do the carbs much good except clean the throats but it is great for cleaning carbon deposits out of the cylinders. Glad you reminded me. I'll post the instructions for doing a decarb. I've seen it do fantastic things to help a motor run better.

[reelcrappie]

Stuff works, I use it on everything, boat motors, mowers, weed eaters, leaf blowers etc..

[Ranger690]

Many times a miss at idle can be a single piece of trash in a carb bowl. A tiny piece of junk keeps the needle (which is attached to the float), from cutting off the gas flow when the bowl is full and the float rises. Thus too much gas is getting to the cylinder. It's almost flooding itself out. As soon as you get above idle, the motor needs more gas anyway, it catches up and runs fine.

I don't know what the carbs are like on your motor, but if you take the cover off, and the airbox and squeeze the gas bulb tight, it should get tight and stop. If you can keep sqeezing and see gas leaking at or around a carb, then the needle is not seating properly.

Dayton