Hi all, i'm shouting to you guys over in the US because i'm stumped (probably because i'm a stupid european.
)<br /><br /> OK, here's a puzzler.<br /><br />I have an aging Mercury 2 stroke 20 HP outboard.<br /><br />Serial No:- 9195125 (note this engine was made in Belgium) my research tells me that this engine was probably made in the late 70's (78)<br /><br />at some point over the weekend it's decided that reverse sucks. when reverse is selected from the remote, the outboard just seems to rev as if she's in neutral.<br /><br />However, if i look into the outboard well and select reverse the prop turns in the correct direction, and even stirs the water a little, but then adding any further revs just results in very quickly increasing the engine revs to ear splitting volume. and doesn't increase the thust.<br /><br />With the engine off the boat i put it in forward gear and turned the prop (sparks disconnected) the prop turns the engine to the point where i cannot turn against the compression. (seems ok)<br /><br />In neutral the prop spins freely.<br /><br />In reverse the prop turns fairly freely with a bit more resistance than neutral (peaking at two points each rotation)<br /><br />Observation is that the propshaft is turning, and not the propellor relative to the shaft. (this rules out bushes and sheer pins right? (I don't appear to have a sheer pin))<br /><br />So conclusion is that i have a gearbox problem, and not something simpler, but what kind of problem?<br /><br />Also are <br /><br />Comments / suggestions folks?<br /><br />Thanks in advance.<br /><br />Alan