90 hp Yamaha Fuel Pump

[foxden]

Went to rebuild by fuel pump on a 1999 Yamaha 90 hp engine. When I opened it up it was totally different from the diagrams in my Seloc manual. No cup and spring, just a thin plastic diaphram on one side and a rubber one on the other. I cleaned and reassembled and can only blow through it in one direction. Since this motor is used, am I missing these pieces or is the design different from the manual?

 

[rodbolt]

Re: 90 hp Yamaha Fuel Pump

and that is why I dont rebuild pumps. for a few dollars more it would be a done deal.<br /> the new pump is about 40 dollars and its not worth the time it takes to clean and rebuild them at 70 per hour. it should still have a spring and cup on the diaphram. if it does not you will need one.<br /> good luck and keep posting

 

[foxden]

Re: 90 hp Yamaha Fuel Pump

I guess it isn't the most cost effective method, but I get tremendous satisfaction tracking down and solving my problems. I did check with the dealer who had an exploded diagram of the fuel pump and it turns out that for the C90 there is no internal spring and cup.