wacky running 'rude

[magoo]

so i have an 85 40hp evinrude.2 cyl.
i idles ok for the most part.
when i give her full throttle,she jumps up to 2 grand stays there a second then boggs her way up higher.almost like i flipped a switch.then it will scream up to a whopping 4 grand then back down to 3 grand then ease its way back up to 4k.
what the HELL?
after this all happened i checked the plugs (champs 77JC4).all oily and black.
could i be too rich.
should i try hotter plugs?

 

[tashasdaddy]

Re: wacky running 'rude

plugs should be gapped at .030. when was the last carb cleaning, and link n sinc. linc n sinc, is the coordination of the spark and carbs so they work together properly. also what is your compression?

 

[HighTrim]

Re: wacky running 'rude

The wet and carboned plugs could mean a mix too rich, too-cold a plug, a bad fuel-oil mixture, bad oil, worn rings, a bad ground on ignition or poor compression.

What were your compression and spark results as Tash asked?

Put the Champ QL77JC4's in her.

 

[magoo]

Re: wacky running 'rude

she does have the QL77JC4 plugs in her.
i just bought this outboard from a mechanic, with a warranty.but he apparently doesnt answer the phone once he gets his dough.
so i have no idea what compression numbers are or when the carbs have been done of linked n synked.
he claims all that has been done.but it sure doesnt run like it.
it seems to run real rich.almost like he doubled my oil.
i guess i will start checking stuff out.

 

[cdoliver]

Re: wacky running 'rude

Has this motor been freshly rebuilt?

 

[magoo]

Re: wacky running 'rude

nope. it sat for a few years. but he was supposed to clean everything and put in a new impeller(i know he did that cause it pisses really well).
i dont think he did any cleaning of the carbs,and frankly i dont want to either.i thought i paid him for that, but im probably wrong.
as far as my rpms go.i just dont have the right prop on it.i boat in denver(5000ft) so i need to go to a 13x11p and keep my 12 1/2 x 13p for sea level.

 

[cdoliver]

Re: wacky running 'rude

I'd find out if the carbs were cleaned, if not, that is the first thing to do. Even if they were, they might need it again. You could take another gas can premixed properly and run it on that can to see if the mix is wrong.If that doesn't help, check all of the internal fuel connections (hoses too) to see if there might be a place where it is sucking air. Did you try choking it or pumping the bulb when this happens? Does the bulb pump up hard and stay hard?

 

[magoo]

Re: wacky running 'rude

at 1 point i checked the bulb and it was tight.wot
at another while idleing i squeezed the bulb and it was loose, and when i squeezed it, it died.

 

[magoo]

Re: wacky running 'rude

so not to sound so new, but when you say clean the carbs.does that mean rebuild em. or just blast some carb cleaner at em.

 

[cdoliver]

Re: wacky running 'rude

If it were me I would try cleaning the carbs first. A carb kit consists of new gaskets, and a needle and seat. Most of the time with 2 stroke motors, the problem is trash in the jets or old oil gummed up in the jets or passageways. Get a couple of cans of carb cleaner in a can, and soak everything in it. you will want to make sure all of the jets are very clean. Blowing through the passageways with compressed air will make it easier. Do a search on cleaning carbs. Someone as definately explained this process better than I can. You will be surprised on how few parts there are inside the carbs.