Any ideas on the knocking that occurs every 3-5 seconds when i accelerate? When we tested the engine in a barrel w/o the prop it didn't do it. But once the prop is attached, it knocks consistently every 3-5 seconds after I give it 1/4 throttle. It doesn't cut out or sputter, just a loud thud and continues to move forward. In reverse it doesn't do it. It's got brand new plugs. Thanks for your help.
SN: e5742528
Model: J8RCTA
SN: e5742528
Model: J8RCTA