electrical system troubleshooting.

[shelbert]

Hi, I am again working on another motor. With you guys help I have managed to get 2 running great for my family. Think we can make it three?<br /><br />I have a 1981 15hp evinrude model # E15RCIS Ser # E0005138, Tiller controled. <br /><br />It starts well and run well in a tub, but on the lake pushing a 14' Jon boat it bogs very badly at anything over 1/4 throttle.<br /><br />I read alot of post here and cleaned the carbs. Adjusted them according to the manual. I installed new spark plugs and checked the fuel pump pressure and lines. All seem to be fine. I am using the tank off my 28 hp that runs great so the tank/bulb/hoses are fine ( it is mixed 50:1).<br /><br />I then checked the compression, it reads pretty close to 100 100 when cold or hot. I also inspected the plugs after my last venture on the lake and they seemed to be oily and wet like they were not burning well.<br /><br />My next step was electrical area. I visually checked the wiring and connection, The only problem I have run into is some splices here and there, they seem to be sound and not loose. I have checked the ignition coils resistance, they are within the specs listed in manual. <br /><br />I attempted to check the power pack and the motor did not seem to match up to the books test procedures, and I am not sure if I even have a sensor coil as I dont know what it is. I assume since the motor is maual start it does not have a charge coil but every time I assume anything I am wrong so who knows.<br /><br />Aside from the power pack test and the sensor coil thing I have about tested everything I can think of, and I would really like to know what is wrong before I go buying things I do not need. So any help or things I should look for would be great. <br /><br />I know this is long but I wanted to let you know what I have done exacly and what I have found.<br /><br />Oh one last thing I forgot to mention, I rebuild the water pump on it before I even tested it on the lake, and it is working well. The engine never really gets so hot I cannot touch it for 10 seconds or more.

 

[The Marine Doctor]

Re: electrical system troubleshooting.

Remove one of the spark plug leads...then start the motor. Repeat this with the other lead. See if this makes a difference in the way the engine runs. The one that does not make the difference is the one that is causing the problem.<br /><br />TMD

 

[shelbert]

Re: electrical system troubleshooting.

I finally got a change to do some testing. Taking either spark plug lead off makes it run very bad, It hardly will go at all this way. Either spark plug has about the exact effect.

 

[shelbert]

Re: electrical system troubleshooting.

Problem has been resolved. It was a combination of 2 things, neither of which is electrial. There are a few teeth missing from the throttle handle gears that were preventing the engine to go to full throttle. It sounded like it was in a Tank but when I looked at the linkage I was only getting about 1/4 - 1/2 throttle. <br /><br />The other thing I did was decarb it very well one night then again with sea foam this morning. The engine ran so good I think im gona do it to my 28 tonight to see if it helps any.