Yamaha no Go

My '86 Yam 70 hp has become so reluctant to start, that now it's a no go, unless I give it a shot of WD40 into each of the 3 carb throats. then it fires up good. The choke mech. clicks when the choke switch is engaged, but for some reason the motor doesn't get that priming snort.<br />Gas-good, priming bulb-hard, plugs-good. What am I missing here?<br />Nevrdun.

Re: Yamaha no Go

Howdy, Neverdun.<br /><br />I don't know how much help I can be here, but I have some ideas.<br /><br />Does your engine have choke butterflies or does it have a primer system? The reason I ask is that they are used differently.<br /><br />With a primer (injector) you press your key in and count to six or eight before you engage the starter.<br /><br />With a true choke, you hold the key in while engaging the starter, then tap it as required while the engine gets going.<br /><br />If spraying WD-40 into the carb throats gets it to start, either you are using the wrong starting procedure or your primer/choke system is not working properly.<br /><br />Maybe someone more familiar with your particular engine can add some ideas here.<br /><br />Good luck

Re: Yamaha no Go

Thank you JB.<br />The carbs have butterflies. I've since got a Seloc manual for the Yam 3 cyl, and will do a fuel pump and filter test. But what puzzles me after examining the fuel flow diagram, --- if there's gas in the float bowl, which is right up there with each individual carb venturi, why can't the shutters suck up enough fuel for start, when it's only 2 inches away?<br />Color me puzzled. <br />I have other boats and motors so I'm never stuck, but what the hay, I want everything to run on command.