Losing rpm- electrical or fuel?

[dsiekman]

01 200 xl carb’d. While under way I will suddenly lose 3-400 rpm. If I give it throttle it will come back up. Not sure where to start looking. Any thoughts?

 

[Faztbullet]

Fuel system and carbs....

 

[Chris1956]

Dumb Question: Is your throttle moving back on it's own? Some will do that slowly if you take your hand off.

An abrupt loss of RPM is usually inadequate fuel supply.

 

[Scott Danforth]

if you can give it more throttle after it slows down, your control is most likely backing off.

 

[dsiekman]

Had my hand behind the control. It is not moving. That was my first thought as well

 

[dsiekman]

I wasn’t WOT at the time

 

[Faztbullet]

Replace fuel pump diaphragm and rivets,only use the plastic disks and discard the rubber ones. Increasing RP increases crankcase pressure to pump....

 

[dsiekman]

Thanks, I’ll give it a shot!

 

[dsiekman]

Rebuilt the pump. It did have some yellow flakes of something in it.