1993 Evinrude OMC 48 hp idle problem, also sometimes stops at high speeds

Jims1

Cadet
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Sep 13, 2012
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When idling are both carbs (for lack of better knowledge) being used?
If I pull the upper plug it stops running, if I pull the lower it still idles (when upper is plugged in).
Someone told me one is used for idling and low speeds and the other is for higher speeds only? I am not a mechanic so no idea.
Another guy said both are needed to idle and it may be electrical problem? They are not mechanics either. I do not have a trailer and am far from anywhere so am trying to repair at the dock. Thank you.

Every once in a while (several running hours apart) the motor will slow down, speed up, slow down, speed up then cut off when running at full or high throttle?
But recently it just stopped while idling in gear.
Easy to restart but would not idle even in neutral. Would run at higher speeds.
After using Sea Foam I can now get it to idle for several minutes at a time but eventually cuts off. It is much better than it was but it sounds as if it idles higher, slows down (like running out of gas) then stops. Runs fine at higher rpm's. I tried to set the idle faster but after having screwed the idle thread all the way in it makes no difference in the idle speed?
Could this be a fuel pump problem?
I replaced the fuel line fittings, bulb, etc. All non ethanol fresh gas, etc.
Thank you
p.s. I did not see this exact problem in the forum archives.
 
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