power loss and surge?

[MCATTACK]

Yamaha 30 hp 3 cyl

just started loosing power and then surge slightly.
I have cleaned all three carbs and checked the plugs
for spark. Could this be slow feed valve as in other thread?

What should i do now?

thanks, Paul

[jones]

Originally Posted by MCATTACK

Yamaha 30 hp 3 cyl

just started loosing power and then surge slightly.
I have cleaned all three carbs and checked the plugs
for spark. Could this be slow feed valve as in other thread?

What should i do now?

thanks, Paul

check your fuel line for air getting in 1st,best way is get the bulb hard and see if it holds it

[alana]

sounds like the fuel pump diaphragm. but check for blocked filters and air leaks first. is the pickup tube in the tank ok, how old is the fuel line and primer bulb. overtightened jubilee clips. the list goes on and on. theres a screw on the bottom of the carb bowls to drain them. open them and see if any muck or water comes out

[Puckoon]

mine was doing something similar, power loss, then picking up, and it was the fuel pump diaphragm