sometimes won't start

Ok so here's the problem. I have recently obtained 20ft pontoon boat with a 50hp johnson outboard. The boat had been sitting unused for about a year. I have rebuilt the carbs and replaced the lower unit grease. The motor now runs great most of the time. It will not idle all of the time. The real problem that I have started happening the other day. The boat was running fine when i shut it off. When I tried to restart the motor it would crank but not start. I finally got it started by removing the cover and and manually opening the butterfly valve on the carb, and spraying some starting fluid in the carb. I have already rebuilt the carbs and used the seafoam that I have read about on here.

1986 Johnson j50belcde
20ft landau pontoon boat

Re: sometimes won't start

did you do all of this http://forums.iboats.com/showthread.php?t=244013?
NEVER spray anything into a 2 stroke carb, other than premixed fuel, starter fluid burns too hot, good way to burn a hole in a piston, and it strips all the llubrication off the moving parts.

Re: sometimes won't start

Thanks for the advice I won't use it again. And yes thats almost exactly the same stesps the manual used.

Re: sometimes won't start

ckeck you fuel lines, air leak, that can siphon gas back. try pumping the fuel line bulb, could be loosing prime.

Re: sometimes won't start

I went out again this morning and it did it again. I checked the fuel line bulb and it was still hard. All of the fuel lines have clamps on them, how do I know if one has an air leak?. . . I forgot to mention at the beginning that I replaced all of the fuel lines in the engine, a new fuel filter, new gas tanks, and a whole new fuel line assembly from the tank to the engine.