I've got a 1980 75hp Johnson Stinger 20" club foot on a 1652 aluminum boat. I've ran this motor a good bit in the last year and it always runs really strong and fast, but will not idle very well. The carbs are clean and have new main jets installed (did not help idle problem). It spits and sputters a mist back out of the top carb and cuts off under low rmps.

I bought a compression tester and the compression checked out weak yesterday @ 79,80, & 85 lbs. Is this low compression possible on a motor that runs strong? Do you think I got a bad compression tester. I tested the motor warm with all the plugs out and at wide open throttle.

Thanks in advance for any advice.

Justin