1972 Johnson 50Hp electric start stumped

[speedoflite2]

Motor was running great on muffs in the yard and then quit would only pop here and there. Has spark, not sure on compression numbers but feels like good compression on both cylinders. I pulled carbs off and cleaned and inspected them. Gas was in both bowls float and needle was working properly. Put back together and tried and still only pops. New gas oil mix in the tank and had out a week ago with new gas. So now what??? Any one else had this problem?? Choke is working. Wont fire with gas/oil mix sprayed in the carbs either.

Thanks in avance.

 

[tx1961whaler]

Re: 1972 Johnson 50Hp electric start stumped

Check the spark with a spark tester.

 

[speedoflite2]

Re: 1972 Johnson 50Hp electric start stumped

I believe my motor jumped timing tdc is not where it should be how do I fix this???????

 

[SS140]

Re: 1972 Johnson 50Hp electric start stumped

How do you know it jumped timing?

Also, "feels like good compression" isnt good enough for you really, you need to rent or buy a compression tester. I just got one last week at Autozone for 20 bucks, it worked fine. It screwed into the plug hole, just be careful you don't cross thread it or over tighten.

You should check the spark, then you can go from the plugs to the coils to the powerpack then timing. I was advised earlier today to refer to http://forums.iboats.com/showthread.php?t=228183 for setting the timing properly.


Just my advice, please correct me if I am wrong. I am new myself.

 

[tashasdaddy]

Re: 1972 Johnson 50Hp electric start stumped

are you sure the plug wire are on the right plugs. if they are in the right place. then ----

it sounds like the woodruff key that connect the flywheel and crankshaft has sheared. you have to pull the flywheel.

PULLING FLYWHEEL

you need a harmonic balancer puller, you need 3 - #8 harden bolts, that fit the 3 holes in your flywheel. standard hardware store bolts will strip out, causing more problems. loosen the flywheel nut, leaving it on so it protects the thread. thread the bolts in 7/16 of an inch. then tighten the puller, adjust so it has a straight pull. now tighten the puller, rap the center bolt with a hammer, then tighten some more. you may have to let it sit over nite, and repeat in the morning. this is a compression fitting, it will eventually POP!!. do not loose the woodruff key that goes in the groove of the flywheel and the crank shaft. then installing the flywheel, it has to be totally clean, no oil, woodruff key in place. then torque the nut to the specifications for your particular motor. if you do not do this, the woodruff key with shear, and you will be repeating these steps.

 

[speedoflite2]

Re: 1972 Johnson 50Hp electric start stumped

are you sure the plug wire are on the right plugs. if they are in the right place. then ----

it sounds like the woodruff key that connect the flywheel and crankshaft has sheared. you have to pull the flywheel.

PULLING FLYWHEEL

you need a harmonic balancer puller, you need 3 - #8 harden bolts, that fit the 3 holes in your flywheel. standard hardware store bolts will strip out, causing more problems. loosen the flywheel nut, leaving it on so it protects the thread. thread the bolts in 7/16 of an inch. then tighten the puller, adjust so it has a straight pull. now tighten the puller, rap the center bolt with a hammer, then tighten some more. you may have to let it sit over nite, and repeat in the morning. this is a compression fitting, it will eventually POP!!. do not loose the woodruff key that goes in the groove of the flywheel and the crank shaft. then installing the flywheel, it has to be totally clean, no oil, woodruff key in place. then torque the nut to the specifications for your particular motor. if you do not do this, the woodruff key with shear, and you will be repeating these steps.

my plugs cant have wires on backwards not long enough it backfires like crazy trying to start I talked to a friend I work with and he said he sounds like the woodruff key snapped off so i have to pull flywheel and check

 

[speedoflite2]

Re: 1972 Johnson 50Hp electric start stumped

pulled th eflywheel tonight and came off like a breeze. Yup definetly the woodruff key Its in 2 big pieces and many metal shavings lying in there under flywheel. Cleaned all this up cleaned the contact points up and bought a 55 cent woodruff key and starts up like a raped ape. Now just have to get to the lake for some fine tuning