1992 Johnson 40hp issue?

[NPG]

I have a 1992 Johnson (tracker) 40hp motor. Its only happened twice but its not right. I will be running full throttle and unit will bog and die. I can fire engine right back up and it will run fine for a couple of hundred yards and do it will do it again. engine will fire right up and it will run the rest of the day. Its tuff to tell if I am losing spark or if its a fuel issue. The last time it happened to me I pump the in line fuel bulb and it seemed a bit soft. Is there anything common with this engine? Any help would be great!!!!!! thanks

[john.wells]

You are on the right track with the primer bulb, but it also sounds like it could be a fuel tank vent issue. I wouldn't put much faith in it being a spark issue, because it would either not work ever or fail at warm temps and stay that way until the coil cools down. You could also have a stuck needle and seat assembly in the carb that loosens up after some fuel runs through. I would first check for proper venting of the fuel tank. If you still have an issue, I would replace the primer bulb (don't be cheap-get a good quality one such as genuine OMC) of the right size. From there it gets a little more technical, but doing a carb job isn't terribly difficult. Some other folks here might have some other simple things to check, but I would start with what I have mentioned and go from there.

[boatfixer]

Yea, It sounds like some type of fuel delivery problem as john mentioned.

Air leak in line somewhere

primerbulb

fuel pump

fuel filter

carburaters

John has a great suggestion for the hose. I've had some good results with after market brand parts, but I always buy OEM brand fuel hoses. Cheaper ones will get stiff sooner and/or won't have an exact fit on the fittings causing air leaks.

One thing to try while you are having this type of problem, is to push in the key. If the motor comes to life briefly, it's a fuel problem. The primer should still have enough gas in it to give it a little shot. If it does nothing, lean towards ignition.