Motor dies when hood is placed over engine

[hunter*11]

I have a 20 hp johnson that I think is an early 70's model. It does not rev up with the hood on it. It starts to pick up as soon as you lift the hood. The farther you lift the hood, the more it picks up speed. Carb has been rebuilt and plugs replaced and gapped.

 

[HighTrim]

Re: Motor dies when hood is placed over engine

What is the model number so we can absolutely pinpoint a motor here.

Are you testing in the barrel, muffs or on the water?

Likely an exhaust leak, choking the motor.

 

[rlb9844]

Re: Motor dies when hood is placed over engine

Your air intake holes in the hood could be clogged. Down here in Georgia, dirt dobbers love making there nest in there. If the holes are clear, than I would say its an exhaust leak.

 

[kbait]

Re: Motor dies when hood is placed over engine

Are the plug wires movement w/armature plate impeded when you put the cowl on? Are the wires getting pushed closer to a ground and arcing out? Model #?

 

[boobie]

Re: Motor dies when hood is placed over engine

If you're running it in a barrel they will do this. If it does it on the lake you have an exhaust leak prob.

 

[F_R]

Re: Motor dies when hood is placed over engine

Repeating,,,If you are running it in a barrel, that is the problem. Period.