2000 Johnson surging

[wili]

2000 J40jplsia

Ran fine all morning on long run back to ramp started surging. 4100 to 5000 rpm at wot.
Have replaced spark plugs, fuel lines including filter, squeeze bulb and anti siphon. Cleaned carbs.

 

[saltchuckmatt]

Fuel pickup tube screen?

Did you notice the fuel primer bulb flattening?

Sounds like fuel but spark could be an issue too.

 

[saltchuckmatt]

We can't hear the engine so for all we know you have a bad tach.