88 yamaha pro 50 idles great then dies

[bigal1346]

I have an 88 yamaha pro 50 which ran great up until this past year. I blew a head gasket which I replaced. I have everything back together and it runs great except after 30 seconds. Then it dies. I'm thinking it is the fuel pump but I wanted other people's opinions first. It seems that it just runs out of gas because I have to pump the bulb quite a bit to get gas back up to the carbs. I rebuilt and cleaned the carbs before putting everything back together so I don't believe they are the issue but I could be wrong. I have replace the fuel lines and replace the clamps to make sure there were no air leaks. Does anyone have insight?

 

[99yam40]

look in the frequently asked questions part of the forum and see how to test the fuel system

 

[bigal1346]

Thanks. I figured out it was the fuel pump. I got the clear vinyl hose and saw that there were bubbles coming through. I checked out the fittings for the fuel pump and the in line was disintegrating. This was allowing air in the lines. My problem is now that it won't get over 2500 rpm. I noticed that the bulb never get hard when I was priming and that fuel was coming out of the top of the bottom carb. Is that by design? I'm am going to probably buy a carb kit and freshen it up. Would this really cause it to run like this?

 

[99yam40]

yes bulb should get hard and no fuel should flow through carbs when not running