Won't start

[isnms]

'70 Mercury 1150, sn: 2840981 <br />She just cranks and cranks and cranks but never turns over. Battery has a full charge on it. The fuel tank filter looks perfectly clean. I did have to take the battery off the fuel tank vent hose, oops. The primer bulb will get hard if the fuel line is not connected to the engine. If it is connected it doesn't get hard. It will get firmer occasionally but never stays hard. I was wondering if it might be a fuel problem, line or pump, since the bulb does not get hard? <br /> <br />I recently replaced the spark plugs but had it out once after that and it ran beautifully. Then the next time out, it would not start. So could it be electrical?

 

[WillyBWright]

Re: Won't start

It could be lack of spark, it could be as simple as a bad primer bulb. It could be carbs, maybe even a bad fuel pump. I'm betting on the primer bulb, but I could be wrong. I like that the bulb gets firm when it's disconnected which would tend to tell me that it's okay. But you should be able to get it to get a bit firm when it's connected. With those carbs, it's easy to squeeze the bulb hard enough to overcome the float valves and get gas dribbling from the carbs. In fact you almost have to do that to get those motors to fire up. If you can do that, then nix the primer bulb idea.<br /><br />Please expand on the fuel tank/vent hose thing...

 

[isnms]

Re: Won't start

vent hose - one of the things to check, from the service manual, if a fuel problem is suspect is a restricted vent in gas tank. That's when I noticed that hose from the tank to the vent had a battery sitting on it. I fixed that but it still did not start. <br />I do get fuel dripping from the carb when I pump the bulb, to much. So unless it's bad fuel pumps or sticky carb float valves, I'm think the fuel system may be okay.<br />The bulb not getting real firm was throwing me in the wrong direction. Now I'm thinking is could be, the first thing you mentioned, the spark/ignition. Or as someone else mentioned timing. I have printed off the Outboard won't start FAQ and intend to do those test next.