Evinrude 100HP cough and low speed problems

[Tempest16]

Hey all,

Have a few issues with my Evinrude 100HP 1980 outboard. This engine has been great to me, it's lasted over 10 years since I bought it and it was even old when I bought the thing. But as I'm starting to realize it is 27 years old, which in engine years is probably about 402, but I have faith, I believe I can bring it back to life!

The main problem is putting along at a low speed, say I'm coming into the dock to park, if I go down below a certain RPM it starts to cough, and about 3 or 4 hacks into it, it dies. This is frustrating especially when trolling and down rigging for some monster pike, or in most cases, a bunch of weeds or an old boot or something.

When I switch it into neutral is idles alright, it still coughs here and there but rarely will it quit. The only thing is it dies instantly when I switch it from forward to reverse, or reverse to forward, it quits fast, the second I switch gears.

Any idea of what I could do? I'm thinking maybe carb problems? Anyways, any insight any of you have would help, i'm not looking for an exact solution, just any opinions you might have.

Thanks

 

[tashasdaddy]

Re: Evinrude 100HP cough and low speed problems

it sounds like it running lean at low speed, when were the carbs last cleaned, jets removed cleaned, and reasssembled with rebuild kits. a small amount of build up can reduce fuel flow. has the engine ever been decarbed. decarbing gets all the old built up crap out of the engine, and brings new life. you 1980 is not old for an evinrude. just broke in. if you troll or idle, at lot after carb rebuild, and decarb, open your plugs, and additional .005. helps with low speed running. we're here to help because we enjoy safe, good running boats. waiting for your response.

 

[Tempest16]

Re: Evinrude 100HP cough and low speed problems

Thanks for the reply,

Well I'm only slowly learning how to fix and take care of an outboard so in the time I've had it, I've never decarbed or taken the carbs apart and cleaned them, although this was the year I had planned on cleaning the carbs. If I clean the carbs and decarb the engine, do you think that will help? It only started doing this last year and I don't run the engine that often, just on weekends during the summer.

Thanks again.

 

[Tempest16]

Re: Evinrude 100HP cough and low speed problems

Which I guess brings me to my next question. After doing much reading on carb cleaning, I've got the gist of it down, take it off, soak in carb cleaner after taking it apart, blow out jets, etc with pressurized air and re assemble. Or the other method os just spraying it with the pressurized spray cleaner and running it through. So my question is, what should I look out for that I can really screw up? Any screws I should count the number of turns or mark their positions? Which method would you suggest I use? The spray cleaner is obviously easier but I'm assuming not as effective?

Thanks for the help guys

 

[clemsonfor]

Re: Evinrude 100HP cough and low speed problems

Get a manual. It will tell you what needs to be set were after disassembly. But once the carbs are clean (if there dirty now) the old seeings mean nothing, because they were se to compensate for dirty or restricted carbs. But Needle valves need to be counted if you have them for you idle speed jets to get it into the ball park but the manual or Joe Reeves post in FAQ will tell you about that. Carbs are easy once you overcome the scaredness of them. Take them apart and watch where stuff comes from the worst that can happen is that you have to take the peices to a marine mechanic and ask (ashamed and embarressed) if he can put it back togeather w/the new peices for you.

-Nate