I'm running a 1976 140 hp OMC on a Viking Deck Boat I recently "inherited". Third day it starts "losing traction", cooking along fine when it "loses it's grip", RPMs go way up with loss of forward progress. Local "experts" diagnose "cavitation", recommend whale-tail fin. Put fin on. Boat works fine for about two hours, does it again. Local experts diagnose "spun hub". Install new prop, boat works fine for about an hour, spins hub (really did, prop and hub came off separately upon removal). Have prop rehubbed, boat works fine for 4 running days (about 20 hours), ground the prop on gravel, shear pin snaps. (Appears gravel is not good to get on). Replace shear pin, boat pretends hub is spun. Replace prop with new stainless steel prop, boat works 10 minutes, pretends hub is spun (it ain't).<br /><br />From reading here (ya'll is SMART!!) I am guessing my engine coupler is giving up (cannot explain the 20 hours the rehubbed prop worked). Is this reasonable?? Will they go out gradually?? Where in the world would I find a coupler for a 1976 140 hp OMC??<br /><br />It is worth mentioning that this is the Ice Cream Boat, and must be restored to service or there will be lots of disappointed kids and scantilly-clad women with cash.
