30hp Johnson starts but

[socgray]

it will idle run at low rpms but it won't open up sometimes while at idle sounds like its running out of gas and as soon as you try to open it up die'salso how do you figure out which carb this has if it needs to be rebuilt

 

[jasper60103]

Re: 30hp Johnson starts but

What year is your motor or post the model number? Also, what's the history? Is this a new to you motor?

 

[jimdd810]

Re: 30hp Johnson starts but

It sounds as if you need to go throught the carb. If this motor has been sitting for a long time then look for the sticky about firing up a long dormant motor.

 

[socgray]

Re: 30hp Johnson starts but

I was hoping the seafoam would help this 1986 30hp but all sign's point to the float in the carb is done

 

[HighTrim]

Re: 30hp Johnson starts but

Is this a new motor to you? It may need some adjusting if so.

Start with the basics.....fuel, spark compression.

 

[Daviet]

Re: 30hp Johnson starts but

Like HighTrim suggested, start with a compression and spark test, if every think checks out it is most likely a fuel problem.
Sea Foam will help keep your carb clean but will not clean it if it is dirty or has passages plugged.
Sounds like it might be time to remove the carb and overhaul it.