I have a 1975 Johnson 115 that is not running well or at all in the water, but will on muffs. My compression #'s are 1- 107 2- 115 3- 112 4- 115. I have freshly cleaned carbs. I put in a new power pack and coils. Before I changed the coils the boat ran up to about 4700 rpm on a 18 foot center console with about 2000 lbs total weight. It wasn't running exactly right before and the coils were cracked so I changed them. I was still trying to get the motor to run its best before I started switching out props.
I verified the engine timing using the Joe Reeves method, but still had an intermittnet miss even though I had spark on all four cylinders that jumped a 7/16 inch gap. I used an inductive timing light and found that the coil on cylinder 2 would skip a beat every second or so. I switched that coil out for one of the old ones that was not cracked and it sounded better and was firing on all four cylinders and the miss was now gone. I thought that I had it fixed at this point.
I took the boat to the boat ramp and put it in the water. I had to tilt the engine up some to get it to crank, but the water intake was still covered. When I took it out it would only turn about 1800 rpm's. I ran it out into the cove for about 1/4 mile hoping it would pick up, and then pulled into my boat slip. The engine cut off before getting into the slip as I backed off the throttle. The fuel bulb stayed fairly hard and pumping the bulb made no difference while the engine was running. Neither did pushing in the choke.
I took the cowl off and was able to recrank the engine by tilting it again. The engine sounded better and would rev well when tilted down out of gear so I backed out and headed back toward the boat ramp. The engine then began to miss and sputter then died and would not start back up. It would fire for a few revolutions then die again. Some one offered me a tow in so I took it back to the ramp. Before the tow I noticed that both cylinder heads were fairly cool, but that the flywheel was warm/hot but not to the point that you could not leave your hand on it.
I towed the boat home, about a mile, immediately put the muffs on it and it cranked and was getting spark on all four cylinders. What am I missing?
I tested the stator about a month ago and it was within specs. I haven't pulled the flywheel, but the stator looks good and is not covering in goo. The timer base seems to be working right. Could this be an issue with the power pack even though it is new? Right now I am at a loss and would like any suggestions since I do not want to just throw new parts at this until it goes away. Hopefully some of you have seen simular problems to this in the past. Thanks in advance Carl
I verified the engine timing using the Joe Reeves method, but still had an intermittnet miss even though I had spark on all four cylinders that jumped a 7/16 inch gap. I used an inductive timing light and found that the coil on cylinder 2 would skip a beat every second or so. I switched that coil out for one of the old ones that was not cracked and it sounded better and was firing on all four cylinders and the miss was now gone. I thought that I had it fixed at this point.
I took the boat to the boat ramp and put it in the water. I had to tilt the engine up some to get it to crank, but the water intake was still covered. When I took it out it would only turn about 1800 rpm's. I ran it out into the cove for about 1/4 mile hoping it would pick up, and then pulled into my boat slip. The engine cut off before getting into the slip as I backed off the throttle. The fuel bulb stayed fairly hard and pumping the bulb made no difference while the engine was running. Neither did pushing in the choke.
I took the cowl off and was able to recrank the engine by tilting it again. The engine sounded better and would rev well when tilted down out of gear so I backed out and headed back toward the boat ramp. The engine then began to miss and sputter then died and would not start back up. It would fire for a few revolutions then die again. Some one offered me a tow in so I took it back to the ramp. Before the tow I noticed that both cylinder heads were fairly cool, but that the flywheel was warm/hot but not to the point that you could not leave your hand on it.
I towed the boat home, about a mile, immediately put the muffs on it and it cranked and was getting spark on all four cylinders. What am I missing?
I tested the stator about a month ago and it was within specs. I haven't pulled the flywheel, but the stator looks good and is not covering in goo. The timer base seems to be working right. Could this be an issue with the power pack even though it is new? Right now I am at a loss and would like any suggestions since I do not want to just throw new parts at this until it goes away. Hopefully some of you have seen simular problems to this in the past. Thanks in advance Carl
