Re: Mercury 135 gearbox
i dont think its actually changing gears, i think your prop is ventialting/ sucking air. my prop does this also. but i know why mine is, its my own stupid mistake. how high is your motor in relation to the transom.<br /><br />your cavitation plate( just abopve the prop) should be about even, within an inch , with the very bottom of the boat. check this out and let us know