1971 Johnson 50HP

[Ronnie O]

I'm a first time boat owner. Bought a small fishing boat with a 1971 Johnson 50 HP. Boat and motor were sitting unused for a few years. Compression on motor is good. Mechanic came by to start it up - sounded like it wanted to start. He says it could be an electrical problem. - no spark. Should I change the spark plugs? Any info will be appreciated. Also, does anyone know where I can get a manual for this motor??? What does hydroelectric start mean?? Do I need to replace something to do with that?

 

[phatmanmike]

Re: 1971 Johnson 50HP

hi ronnie. first off, hydro electric refers to the way the transmission shifts, or the LOWER UNIT.<br /><br />you can buy the manual here at iboats.com or at ebay.com<br /><br />if there is no spark, there is a number of things that can be check. usually start from the plugs and work your way backwards, all the way to the junk under the flywheel if need be. with plugs removed, both, place one plug into the boot and hold against block and turn motor over, you should see a hot blue spark. if its yellow or orange, it is weak. or use a timing light on the wire to see if it has spark. <br />those powerpacks can go bad at any moment, and there is one on ebay right now...<br /><br />what did your mechanic do to come to the " no spark" conclusion. usually if they sit for a few years, its a fuel problem, but electronics can go bad at anytime.<br /><br />you have a good motor, i have same thing, mine is 1972. they are reletively light and they use the larger gearcase wich enables you to run a larger prop and get mor "bite" out of the water.<br /><br />email me direct if you need any specific help/suggestions with that motor, as i have a couple of them at the current moment.<br /><br />mike<br />phatmanmike@yahoo.com or spincycle9@hotmail.com

 

[spike440]

Re: 1971 Johnson 50HP

I have one of them too. I just put a water pump kit in mine. I got my manual off ebay for like twelve bucks. Good motors

 

[OBJ]

Re: 1971 Johnson 50HP

Ronnie....just a few things. <br />Get a spray bottle and put some premix in it (gas/oil) Spray a few shots down the throat of the carb and see if it will try and start. If it does, then the problem is fuel which sounds more like the problem than fuel.....I could be wrong on this one.<br /><br />Check the wiring. Some of the wiring on older models tend to get brittle and the insulation starts to fall off. Pop the flywheel and check the coils are not cracked. This could cause them to go to ground causing a "no spark" problem.<br /><br />After setting a few years, it would be a real good idea to change out the water pump impeller. They are rubber and tend to lose their memory and get hard. <br /><br />Remember to only use lower gear lube made for electric shifts such as Bomby Premium Blend. Make sure it says "For Electric Shifts" on the container.<br /><br />It would be real good to go over the fuel system and rebuild the carbs and replace the fuel lines which I would bet are hard and have lost their flex. <br /><br />Once you have her running, give her a good decarb to get rid of any built up carbon in the cylinders and around the rings.<br /><br />As posted before, get a service manual for the engine. OEM's are the preferred manual but for minor maint. work, generics will do.<br /><br />Keep us posted as to your progress.....thanks.

 

[Ronnie O]

Re: 1971 Johnson 50HP

Thanks guys for all your advice. I will be contacting you again soon. The weather is not cooperating so I can't get out there to work on the boat. <br /><br />Quick question - I checked out the manuals on ebay. The only one available right now is for 1973 and up. Are they basically the same info or should I spring for a new manual????

 

[phatmanmike]

Re: 1971 Johnson 50HP

look for the manual titled"2 cylinders 1971- 1989" thats what i got and it works wonders. <br /><br />obj has some good advice except that the coils arent under the flywheel they are mounted to that big wire mess in the back. let us know how it all works out

 

[JB]

Re: 1971 Johnson 50HP

Ronnie O.<br /><br />There is a systematic troubleshooting procedure in the FAQ section, "Outboard wont start". <br /><br />Give it a try.

 

[karrick]

Re: 1971 Johnson 50HP

Ronnie<br />If you don't want to buy a manual, although I reccomend buying one, check out your public library. I own a 71 60hp 3cyl. I found the wires exiting the powerpack were very brittle. This could cause a "no spark" issue assuming the 50hp model is setup the same as mine. Keep posting questions<br />Karrick