Key switch left "ON", Johnson 25hp 3-cyl.

[Grumman59]

I have a '98 Johnson 25hp 3-cyllinder 2-stroke which up until now has been fine. However, when I put it away for storage last season, the key switch was left on, probably because I ran the gas out of the carbs and then omitted to switch it off.

The battery went flat of course since there is a draw for the voltmeter and the monitor guage etc. So my question is, was this likely to have "cooked" any of the electrics or electronics in the engine?

The engine has been running strangely since, starting right up just fine but then missing shortly afterwards. I've researched some of the likey causes of the rough running and will start another thread about that but it would help to know if something was damaged by my mistake. Thanks.

 

[Silvertip]

Leaving the key on has nothing to do with how the engine is running. Keep in mine the engine does not even need the battery to run because it is a magneto ignition system. The battery is only used to spin the starter and run the "boat" related electrics. Just don't ever run the engine with the battery disconnected as that can damage the rectifier in the charging system. Chances are the carburetor(s) are due for a thorough cleaning. There are a couple of schools of thought on running carburetors dry. Just for the record, they cannot be run totally dry -- there will always be a little fuel in there. One school says at the end fo the season, treat the fuel with Stabil, SeaFoam or any of the other fuel stabilizers and then run the engine long enough to get the treated fuel into the engine. Then just put it to bed. The thought is if there is little or no air in the carb it won't get gunked up. The other scenario says run it with the fuel line disconnected which as I said earlier cannot eliminate all the fuel. With air in the carb and no treated fuel to protect it, gunk and varnish can form. There will be disagreements to be sure. Do whatever works for you. But an engine that ran fine last fall and not in the spring likely means there is a fuel system issue and those issues are almost always carburetor related.

 

[Grumman59]

Thanks, that's good to know. I was thinking of how leaving the ignition switched on in an older car would probably burn out the coil etc. Anyway, the alternator still cranks out ~14v and the stator resistance readings are within spec.

I don't think it's fuel related. This motor is very low time and is mostly like new. And I'm very careful about gas, only using non-ethanol with stabilizer added. Both pump screens were perfectly clean as was the in-line filter. Every time it starts, it runs perfectly for a short time, then starts to misfire. One other thing I did last season was to use some rather thick storage spray and I'm wondering if it may have affected some of the connections.

I'll do some more tests and maybe ask more specifically in the Johnson/Evinrude section.

 

[gm280]

Grunman, maybe if the future when you store your boat for the winter season, use a little battery trickle type charger to keep the battery fresh. Any battery that sits for any length of time, will shorten its life. Keeping it charged and fresh will be the best thing you could do for it. JMHO

 

[Grumman59]

I do usually. I have several of the small Schumacher trickle/float chargers but in this case, where there was no 110v power available, I used a small solar unit. I guess it wasn't enough to feed the drain.

Incidentally, the deep cycle battery was totally dead but after a couple of days on a charger in desulphation mode, it's come back to life and seems fine.