Ok so i about 7 months ago my father passed away and i stoped going out on my boat. I pulled it out last mouth and took it out and it was ok for one trip. On the next trip i lost spark. I replaced the trigger and it started for a minute then just shut off. I now cannot get it to start. I have a nice blue spark and timing is correct. So i just checked the compression and all four cylinders are at 60psi. before i had 118-121. What will cause me to lose compression to all cylinders at once?