I have a 1990 70 johnson that just lost spark on all three cylinders. I started it on muffs to make sure it was gonna run,anyhow i let it warm up then shut it off. I came back about 20 mins later and turned the key and i got one loud backfire out of the exhaust and it hasnt fired a spark plug since. Last time i ran it on the water i did notice it took alittle longer than normal to get it to start, but other than that it ran great. Im leaning toward a timer base or a power pack problem. i replaced the powerpack two years ago due to one cylinder losing spark. Does anyone know an easy way to check to see if the timer base is sending a signal to the powerpack. All fuses are good and ofcourse plugs are fuel fouled right now. I do have three new plugs ill install when i get it firing again. Any help would be appreciated. Thanks.
