73 Mercury 9.8 Problem

[DTS1290]

Last summer I bought a '73 Mercury 9.8 HP Model 110 and after a set of new plugs it runs fine. The engine will go to WOT in neutral and reverse but once in forward gear it won't go anywhere near it.<br /><br />One other thing about this motor has been puzzling me. This motor has a trolling switch at the base near the pivot and I have absolutely no clue what it does. Anyone knows I would greatly appreciate the information. Thanks!

 

[Laddies]

Re: 73 Mercury 9.8 Problem

The lever marked troll on the swivel bracket allows a bracket to drop down and the engine to run at a half tilt position at idle speed. Do you mean the throttle won't advance in Fwd gear or the engine simply won't rev up?

 

[DTS1290]

Re: 73 Mercury 9.8 Problem

The throttle advances in forward but the engine revs only to about a quarter of WOT revs with the throttle advanced to full. The revs do seem to peak just slightly before the lever is cranked all the way to full.<br /><br />Also, does the gearing ratio differ from reverse and forward? The prop pitch was pretty aggressive for our boats weight. I bought a three blade prop to help. Think that will make much of a difference?