2000 Johnson surging

[wili]

I have a 2000 Johnson J40jplsia that will run good for most of the day then all of a sudden loses power and yesterday started surging. I tried squeezing the fuel bulb but had no effect and was firm.

I have been chasing my tail for a while. I have had carbs cleaned. Replaced fuel lines, squeeze bulb and anti siphon.

I have attached a video of it surging yesterday.

Any thoughts?

 

[saltchuckmatt]

Probably fuel related

 

[racerone]

Test run with another tank.

 

[wili]

Test run with another tank.

Will do

 

[cyclops222]

Haw about correct new sparkplugs. And check the gap on each new plug BEFORE installing them.

 

[wili]

Haw about correct new sparkplugs. And check the gap on each new plug BEFORE installing them.

Done it last month

 

[saltchuckmatt]

Assuming this is a 2 stroke, probably shouldn't use it at high speeds until you figure it out. A lean situation is never very good for them.