1977 Evinrude 115hp

[MCM]

Re: 1977 Evinrude 115hp

Just a thought but this on again off again starting could be an indication of a failing power pack or other ign. component. If it happens again you should check for spark if its not starting back up.

 

[vano6990]

Re: 1977 Evinrude 115hp

mcm that is the funny thing about it. While we were looking at the motor due to the initial problem we hooked up a spark indicator and were not seeing a spark. Then a few minutes later we disconnected the spark plugs etc and reconnected them an it started up. Dont get me wrong not a spark plug problem but something else. I was thinking about powerpack etc. Would the powerpack only work a certain times? The new spark plugs work great and I think I am getting better mileage.

 

[MCM]

Re: 1977 Evinrude 115hp

The power pack can behave or work intermittently before it quits all together, so can the timer base and the stator. There are tests that can be done with a digital volt/ohm meter on the stator and timer base, the p/pack's a little different. On the stator, visually isnpect it for cracks or a sitck, syruppy substance dripping off of it to begin with, also if you have a tach. is it working?

 

[vano6990]

Re: 1977 Evinrude 115hp

Thanks for the reply Mike. I examined the stator under the flywheel and it looks new. Fresh green paint over it and no sticky, syruppy substances. As for the tach I am not sure if it is accurate. I may be pushing it higher than 5200-5600 when it reads 4200-4500? Is there a certain brand I should buy to replace it. I have read that is so. I assume omc is my choice? I have no problems with backfires or anything like that when it is running. So would that rule out the timer base? What does a timer base do? Tomorrow is my payday and I will be ordering the owners manual and the service manual for my specific motor. Do these sound like serious problems or just routine for the older models?

 

[vano6990]

Re: 1977 Evinrude 115hp

P.S. do you know what signs the motor would make if the power pack was working intermittently? It was wierd when we connected the spark indicator and no spark was seen in a couple of trys then without changing spark plugs or any motor work it started fine and showed spark. Although my friend stated it wasnt blue and snappy but I guess orange. I should have looked while he hit the starter.

 

[MCM]

Re: 1977 Evinrude 115hp

The power pack could behave just like that, some components become sensitve to temerature when they start to fail, sometimes they just quit without warning. There's an ohm test you can do on the timer base, you should get 15.0 ohms +/- 5.0 between the leads at the power pack with the leads removed and the meter set to LO ohms, also I think you can test the cranking voltage of the power pack by testing at the ign coil terminals on the p/pack. remove the coil leads to test, You should get a minimum of 125 volts AC output to the coils when cranking. Anyway your manual can explain it much better than I can probably

 

[Solittle]

Re: 1977 Evinrude 115hp

If you have a friend that knows something about outboards you might ask for some help since you are new to this.

 

[vano6990]

Re: 1977 Evinrude 115hp

The motor ran decent at aprox 5200 rpm but I read somewhere the test tank RPM should only be 4800. Does anyone know what the WOT should be for a 1977 evinrude 115hp outboard? model 1157793S Serial #j0001310. I think my tachometer is not reading correctly? Because when I was running it at 5200 rpm it made a wierd noise then as I pulled off the throttle it stalled/flooded. I waited a few minutes cranked a couple of times without the choke then once with and it started right up. Continued to work fine during our two day trip??? I know I need to get the owners manual (working on it).

 

[kevin88]

Re: 1977 Evinrude 115hp

Flathead, the intermittent problems that you are describing are, in my opinion, warning signs that something is damaging your power pack or already has. In my own experiences a rusty boot on the spark plug killed 2 power packs (1 new and 1 old)before I found it. It would act just like you described above with the WOT RPM'S not hitting the best numbers, not starting at times, and the starting right up at others. Even if it's not the cause of your problem I would recommend replacing all the ignition wires and spark plug boots on your machine if you haven't done so already. They don't cost much and they can kill a power pack when they go bad.

 

[Dhadley]

Re: 1977 Evinrude 115hp

Just to answer your question about the rpm -- the test tank or rpm with a test wheel is rarely the same as the operational rpm. Its merely an rpm that is achieved with a given test wheel on a given motor. A reference point so to speak. <br /><br />Thats the tech's way of determining if there is a problem with the motor or boat. When we're looking at performance issues thats the quickest way to "seperate" the motor from the boat. If the rpm's fall short on the test wheel then we start to look for issues on the motor itself.<br /><br />On your motor we find that if its set up at 5800 with an average load, the motor will live the longest. With that set up the combustion temps, on todays fuel, stay within design parameters. Whether youre cruising at 3000 or 5800.