Johnson Outboard Troubleshooting

[jkca22]

I've got a 1978 9.9 Johnson outboard, and I am having trouble keeping it running. I can get it started but it always dies very quicky if I don't keep the rpm's up. It will not stay running unless at full throttle, and then its not runnig as fast as it should. <br />What could the problem be?<br />I have checked the spark plugs, fuel line, fuel filter/pump, and I think the carboratuer is ok because have taken it apart recntly.<br />Any ideas would be appreciated.<br />Thanks

 

[plywoody]

Re: Johnson Outboard Troubleshooting

It could be lots of things, but it sure sounds like fuel to me. I'd rebuild the carb for a start, if all other things regarding fuel from the tank vent to the pump to any inline filter and there are no pinholes in the hose or anything like that.

 

[Valv]

Re: Johnson Outboard Troubleshooting

Try to start it and squeeze primer buld while running, if motor keeps going, you have a fuel pump problem. At least this will eliminate some of the issues and you can concentrate on other possibilities.