Need help with motor problem

[10point]

My motor was running slow so I messed with the fuel pump and got it running at normal speed. Now my problem is that is making popping noises periodically while it is running. When it does this it shakes and a puff of smoke comes out of the prop. Any ideas? By the way this is a 1974 Evinrude 9.9

Edited May 19, 2010 by 10point

[Big Cliff]

My motor was running slow so I messed with the fuel pump and got it running at normal speed. Now my problem is that is making popping noises periodically while it is running. When it does this it shakes and a puff of smoke comes out of the prop. Any ideas? By the way this is a 1974 Evinrude 9.9

 

Kind of like it is going to stall but then keeps going?

[10point]

I would say it is like it is going to stall. Just a loud pop, smoke, and keeps on running.

[fishhunter]

If its a flat top it would have points and condenser. change them. They are not much and you will find your motor will run better. and change your plugs too.

[10point]

If its a flat top it would have points and condenser. change them. They are not much and you will find your motor will run better. and change your plugs too.

 

I meant to say it is NOT like it is going to stall. What does flat top mean? I have changed the plugs.

[Big Cliff]

Well, without actually seeing it, from what you describe, it could be running too rich, some fuel escaping to the exhaust then firing which would account for the "pop" sound and the puff of smoke. When you changed the plug, was it black and carbon build up on it or was it grey/tan and clean?

[10point]

Well, without actually seeing it, from what you describe, it could be running too rich, some fuel escaping to the exhaust then firing which would account for the "pop" sound and the puff of smoke. When you changed the plug, was it black and carbon build up on it or was it grey/tan and clean?

 

I believe it was black, I still have them out in the boat so I can look at them and make sure. I guess it would help if I did a video of it and posted it here? I can probably do that in the next few days.