c40 losing rpm's

[ruger243]

I have a 1997 Yamaha c40 3cyl. It runs perfect at idle and midrange at wide open throttle (WOT) it will lose rpm"s, I can back off of the throttle and then open it back up and it will pick back up to 5,200 rpm"s for a short time and then lose rpm"s again. This will happen for a trip or two then it will run perfect at WOT for a trip or two. I have replaced every item from the fuel tank to the fitting on the motor, fuel pump included. Would a faulty carb act this way? What else should I try to replace?

 

[Tasker]

Re: c40 losing rpm's

Sounds like water was in the tank, but not allot. Its sounds like you burned it out. If you dont have a water sep filter, then get one.

 

[ruger243]

Re: c40 losing rpm's

There is not any water in the fuel! I've checked this multiple times by pouring the fuel into a glass container, as well as have a water separator on the fuel line. I guess I'm going to try to rebuild the carbs and hope for the best.