I have an '84 Suzuki DT60. It has been in the family since about 1990 on a pontoon boat. A few years back my father decided it was too noisy and bought a 4-stoke Yamaha 70 to replace it. We ran it out of fuel and pulled the Suzuki and stored it upright in the shipping stand in a barn. This year I sold it for him and helped install it on a different boat. Fresh plugs, gas, and fresh oil in the oil reservior. Starts and idles fine. Revs like a champ in neutral, but has no power at speed-it just bogs down. I pumped the fuel bulb while underway and it is rock hard, no difference in performance. No gas coming out the vents in the carbs. I am a pretty good automotive mechanic, but I don't exactly know where to turn here. What should I look for? I believe it to be an ignition problem of some sort, but is there a module I should look at? Coils? Pickup? I need a bit of help so I can complete the sale. It has been a great motor and we have another DT75 that was bought new in 1986 and in 24 years has only needed a fuel pump and a starter rebuild other than maintenance. Thank you for any advice.