I have a 50 hp yamaha tiller that is having some issues. I pulled it off the river on friday and noticed I had lost about half of my oil on the run from eagle rock to centennial. Motor runs & idles fine. I replaced oil and filter, cleaned the air intake and Located the leak( a gasket) and brought it to river & sea because they could get me in right away to fix it. Anyways, I bring it into the shop and they hook it up to their rabbit ears and It begins idling at about 1600 RMPS, which is high obviously. It didn't do this on the run in or while loading the boat onto the trailer. They claim that it now needs a new idle control valve, which they cant get until friday at the earliest. (why they couldn't get overnight shipping I don't know) Im Wondering if they are trying to pull something over on me ( I have heard stories about this shop) or if It just needs the idle screw adjusted. Does anyone have any Ideas if that is what it really is or if there is a more simple fix.