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76 jhonson 15hp no spark

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outback32

Regular Contributor
hello everyone I'm working on my neighbor's motor. its a pull start 15hp that accidentally went for a swim. This happened last year and im just now getting into it. First it was siezed but i got it broke free. then i tested for spark and it has nothing. The driver coil underneath the flywheel showed 1.6ohms. should my next step be to clean the points. I should add that everything under the flywheel looks great. when it first happened he blew everything out with a air compressor. took plugs out and blew the water out of the cylinders. he said it had spark then so im hoping its just dirty contacts. im open to any and all suggestions thanks
 
If it sat for that ling with water inside the fine bearings are likely scrap.--------This motor likely won't run for long if you do get it going.------But clean the breaker points and see if spark returns.
 
Any engine that's been submerged...... If the engine isn't going to be restored to running condition immediately, it's better to let it stay underwater until it is. Once air (oxygen) hits it... the rusting procedure begins. In your case, the crankshaft, connecting rods, all bearings, wrist pins, piston rings, etc etc are pure junk.

If you do ever get it running, I'd suggest you get away from it quickly!
 
I guess il start with the points and see if i can at least get spark. im just trying to get it going for my neighbor. is there anyway to tell if the motors shot without tearing into the case
 
You will have to look at the crankcase to see what damage that the water caused. You can access that by removing the reed block. The motor may run fine once you get spark, but its life has likely been shortened. Pitting on the bearing surfaces will dictate its longevity. Do a compression test later too, and we will get a better idea if your neighbor's motor is a gonner. The parts are valuable regardless. It is probably still worth a few hundred anyway, running or not. Water recoveries should be acted on within a few weeks max.
 
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Manuals say " get it running in 6 hrs or less "--------Or submerge again in fresh water and arrange shop help.------Took a 53 model 25 HP apart after less than 24 hrs after recovery.-----Bearings showed signs of damage already.-----Took a 1955 model 15 hp apart within minutes of being submerged for 3 weeks.-----No damage on any bearings !!
 
Better advice, Racer, the sooner the better. Reminds me of the time my neighbor was giving his father in law driving lessons in his Jeep and they somehow decided to see how long it would float on its roof in my pond. NOT LONG! We got it running within 2 hours. Guess he flunked the driving test.
 
im getting ready to take the poinits out and clean them il see if i get spark then. il report back with my findings hoping i can at least get spark.
 
cleaned points and regapped them I now have spark on the bottom cylinder but the top is still dead. would the coil be the next step in the process.
 
I swapped coils top and bottom. I still have no spark on the top cylinder. so im assuming the coils are good. what would cause the no spark on top cylinder if the coils are good
 
Try swapping the points. You will then find the problem. You could try swapping the condenser first, its easier. If still no spark, then gotta be points. You could also just check the suspect points for resistance with an ohmeter. There cannot be any resistance, compare the reading with the points on the sparking cylinder.
 
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man you guys are life savers I will try what you said in the morning. thank you both hope to have better news in the morning. on a side note a guy at work has a 9.9 its a cdi motor. he says is locked up. I think i could get it free should I pick it up
 
You can turn the 9.9 into a 15 by swapping your carb. The 2 motors are one in the same. I like to swap out the carb butterfly cam ramp too, from the 15's, but not sure if it makes much difference. This is the ramp on the stator plate, that contacts the carb butterfly when you throttle up.
 
Just set your multimeter to the ohms scale. Make sure you turn the crankshaft to have the points closed. There can be no resistance whatsoever. In other words, you will get the same reading as when your 2 ohmeter leads are touching each other. One wire, of course, will go to a ground and the other ohmeter wire will go to the points.
 
I tested points regapped points and swapped condensors. I still had no fire on one cylinder. so I cleaned both sets of points really good again. and what do you know i now have fire on both cylinders. so next im starting on the fuel system. im going to remove the carb and clean it. im guessing i should clean and rebuild or replace the fuel pump. do you think id be better off cleaning or replacing the fuel pump. and is there anything else i should look at in the fuel system. one other thing I put 2 cycle oil in the cylinder to unlock the engine. is there a way to flush the oil out or wiĺl it be ok. Thank you guys again for all the help.
 
Good, remember what RACER said about having the points CLEAN. The fuel pump may be okay. If the carb looks clean, you might not have a problem, just check the screen for dirt and debris. The residual oil shouldn't hurt anything so go ahead and try it.
 
When checking float level, simply flip carb upside down and observe if the float rests parallel with the machined surface where the float bowl seals. Careful to apply no pressure to the float needle as it seats. The tip on that needle can easily be damaged.
 
well i got the carb off and its bad. ive never seen rusty milky water in a carb.
fuel lines had water in them so i replaced the line. I have the carb apart getting ready to clean it. should i dunk the whole carb or just spray everything with carb cleaner
 
Oh Joe, it can't be that bad. We gotta give this guy some hope.
You said it happened "last year", are you meaning Nov or Dec.? Your just trying to help the neighbor I have done the same myself. Dismantle, soak and physically clean, re use gaskets or whatever you can to save buying any parts. Push some fresh gas through the fuel pump with the squeeze bulb, see if it goes through and notice what has pushed out the carb supply side.
Next, if gas can pass through, don't worry about rebuilding the fuel pump yet, you can still run the motor by squeezing the primer bulb.
 
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no offense but its my time and i dont feel like im wasting it. im enjoying the process if it runs when im done great if it doesn't. i feel like ive learned useful information along the way.
 
Joe is one of our top techs. He may be right, but for you its a learning experience while trying to make something useful out of a possible "boat anchor". I started out the same way, Dad said I was waiting my time too. My Dad is my hero, he directed me to take on challenges, some you win, some you loose. For me it was more about not giving up, showing Dad that what couldn't be done, really could be done. There can be much gained in "time well waisted".
 
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outback32 said:
no offense but its my time and i dont feel like im wasting it. im enjoying the process if it runs when im done great if it doesn't. i feel like ive learned useful information along the way.
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Yeah, okay... perhaps I was slightly out of line with that short statement... my apologies. It's just that from a professional standpoint from whence I stood for many years, and having been down that flooded road of submerged outboards countless times... unless they were worked on immediately after being exposed to the elements, the story always ended the same. However I wish you luck in your endeavor and acknowledge the education you're obtaining in the process.
 
Thanks, Joe, you are one awesome guy. Remind me of my own Dad, but your a helluvalot better at fixing outboards.
 
like I said im just trying to help a friend and neighbor. learning along the way if it runs great if it doesn't. oh well at least I tried and it will help me in the future. ive owned boats for about 15 year's now. I never worked on them much because i had a work friend that was a great mechanic. sadly he committed suicide 2 years ago. so im doing what I can to learn as much as possible. with the great help on here to work on my own engines. because there are very few boat mechanics left around here. anyway the carb is apart awaiting dip. ive replaced the fuel line and got the diaphragm apart. hoping to be able to try to start it by the end of the week
 
Sorry about that friend, our lives are so different today, suicides are on the rise, especially among our youth.
Try that fuel pump test and you might get lucky. A compression test would be helpful too. I have freed up many motors and about 1/3 rd of them have run for many years. If the initial compression test shows say 90 psi, and after about a good days run, it comes out the same, or a little higher, then you got a good chance of success.
 
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