Re: 6hp no spark
These motors are very simple to work on. You will have to pull the flywheel to get at the ignition parts but changing the coils, points, condensor and the wires, if need be, is simple. Do not pull the flywheel with a jaw type puller, however, because you may break it. Use a harmonic balancer puller or the OMC puller, which is available at your local OMC dealer.
I took the points and condensors out of mine and replaced them with a set of Brian Miller's NOVA II electronic ignition modules. They work great and you don't have to worry doing future ignition system tuneups. If you don't mind spending the money, I recommend replacing both coils and spark plug wires (unless, of course, they have been changed recently) while you have the flywheel off. Once those things are done, you shouldn't have to pull it again for a long time.
Rebuilding the carb is also very simple on this motor, as is replacing the water pump impeller. One thing that confuses some people on this motor is how to disconnect the shift rod linkage. Just unbolt the lower unit and drop it about a half inch - inside you will see the coupler. Loosen the upper screw and remove it so that the detent in the shift rod is free. Once this is done, it will come off easily. Putting it back together is a little trickier because there isn't much room to see inside but you can help things by positioning the gear shift handle in reverse to push the shift rod in the motor down. Once you have the screw back in, give it a gentle tug to make sure you haven't missed the detent and push the lower unit into place. Be sure that the water tube is properly seated in the water pump housing as you do this.
If you need to take a look at the thermostat, it is located on the top of the back portion of the block, immediately adjacent to the head. It is triangular in shape and has three bolts.
These are great little motors - have fun with it!
