Our older 25 hp outboard was crusing smoothly across the lake when it very suddenly powered to almost stop. Alittle nursing and it went up to about half power. Went to trolling motor for awhile then it took me in but ran very rough. I thought I might have hit something but no damage on lower end. then I checked plugs. I run on either one o.k. but again very rough. So plugs are not it apparently. Any idea what happened?
Make (of engine): Johnson
Model (of engine): J25TELCEM
Started and ran it on one cyliner (disconnected one plug) and it runs on both.
So you have spark on both cylinders
Yes. Disconnected one plug, started and ran. Stopped and repeated on the other.
Did you look at the spark?Was it blue?
No. I just figured that if is ran with one cyl it has spark. I will have to check again tonight after work and get back to you.
I repeated test (one cyl at a time) but could not -- don't know how -- to detact blue spark. I just know if it is running with only one spark plug
connected that plug is o.k. Or am I wrong about that? If so how do I
check for a blue spark?
you need to buy a adjustable spark tester at the auto storeset it to 7/16 of an inch
O.K. but this too will take some time -- we live in Silver Valley Id very remote and low population. Auto parts closed by time I get off work and closed Sunday. Will update Moday evening or Tue a.m. Thanks
Ok take your timeYou could make one with a 2x4 and nails
Went to two auto parts. No ADJUSTABLE spark tester. Yes they gave spark plug tester but it is not adjustable and you can't see the spark. It just indicates if there is a spark and we already know that because motor runs with just one connected (and it runs with the other connected - one at a time) So both plugs work.
Four mechanics have told me both plugs work so problem is something else. Appreciate your efforts but I will try and hook up with outboard repair shop and take it in.
hello,do you still need help.Capt Ron
Yes but I'll have to get it from repair shop. Auto parts here (two of them) do not have an adjustable spark tester. So, since you say I have to
"see" the spark or use adjustable tester (set to 7/16th) and I can't do that my only hope is Johnson repair shop.
Again your going after spark does seem to be off the mark since engine runs on each of the two cylinders (one at a time). Thanks anyway.
Hello,i am Capt Ron,the other mechanic opted out,i will try to help you,have you checked your fuel,did you just fill up your gas tank when this happened?
Not new fuel. Thing uses very little, plus I am in fishing area quickly so this is same fuel I have been using. Like I said, going along quite nicely at about 80% throttle. Then, like I hit something, motor throttled down to almost idle. Have checked lower end out of water and find no damage.
After letting is 'rest" (using trolling mtr) is ran at high speed (about 60 to 70%) to get me back to launch, but running very rough -- not smooth as before. At home (with ear muffs) it runs at all speeds but rough.
when you pulled the spark plugs,how did they look,color,any metal,wet?
Wet. Will be in the 'city' tomorrow (100 mile round trip) and am going to try and buy two new plugs just to try that and see if it helps. Then maybe pull the gas line (from tank to motor) and see if it flows o.k.
What say you? (you do sound more interested then the former mech.)
were both plugs wet,if so,do a compression test,it is possible you blew a head gasket,or your carb is flooding due to a sticking needle and seat.Capt Ron
30+ yrs. exp. Own a mobile marine shop in SW Florida