1979 Evinrude 25 HP engine problems

OK, well my friend has a 79 evinrude 25 hp outboard 2 cycle engine on his boat... it was stored for 2 years and had a fresh carburetor rebuild before storing it. Anyhow, he started it up and it ran fine the very first time he cranked it after sitting for 2 years. Then all of a sudden it wouldn't start anymore...He said that he just used the old gas that had been sitting. So we went and got a new gas tank and mixed it 50:1 like it calls for and finally got all the old gas out of the carburetor and engine. Then we went over to NAPA and got a carb rebuild kit...and we changed all the mating gaskets along with replacing the old needle valve bearing, and the grommet/gasket that the needle valve threads through... well the engine starts and it only runs if we play with the throttle... like it backfires at low throttle and it wont idle on its own at all. so my question is... could bad coils cause this to happen...aslo we replaced the spark plugs too... and is there anything I can do to like blowout the carburetor with some compressed air or anything...like taking the freeze plugs out and just shooting some compressed air in there? then replacing them with the new ones provided by the kit? Im just really stumped...he had the thing running each time he started it at his house then when we went to take her out she wouldnt idle on her own and backfired and all....any help is greatly appreciated.

Re: 1979 Evinrude 25 HP engine problems

anyone have any info on this at all??

Re: 1979 Evinrude 25 HP engine problems

Ttt

Re: 1979 Evinrude 25 HP engine problems

Has anybody had the flywheel off? Sounds like maybe a sheared key from improper installation and/or torqueing.

Are you sure the orfice jet in the bottom of the carb bowl is clean?

Do you have good spark? Does it jump a 7/16" gap?

Have you checked compression?

Until these questions are answered, we are shooting in the dark.

Re: 1979 Evinrude 25 HP engine problems

yes the jet has been totally cleaned...we took the carb apart as much as possible, and cleaned it all out... we have really good spark...and u may be right about that flywheel key... and it jumps atleast a 7/16" spark. is it possible for a carburetor to just go bad?

Re: 1979 Evinrude 25 HP engine problems

i fixed the engine...i got it started and idled it by hand on the throttle... then i hade my friend back the needle valve out to get a little more air/fuel mixture in there, then i idled it a little more by hand just to where it barely runs and had him adjust that screw to match my idle speed so it's all ready to go...I just have to replace the water pump now...one of my friends roomates had it running withought water we think, but the engine is ok...so, alls well I hope...any important info on replacing the water pump or is that pretty much self explanitory?

Re: 1979 Evinrude 25 HP engine problems

Im really new to marine engines...can somone tell me where to locate the water pump on this thing.... is it in the stern drive? again its a 79 25 horse outboard evinrude

Re: 1979 Evinrude 25 HP engine problems

its in the lower unit on the bottom of the leg where the propeller is ....easy to change out with a manual.