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1974 9.9 hp Evinrude dies after 20 seconds to 3 minutes, time varies

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code1p36

Regular Contributor
My 1974 Evinrude 9.9 HP dies after running perfect for 20 seconds to 3 minutes. Time varies so I am not sure exactly what it is. First thought was fuel pump wasn't working. I had to rebuild anyways because it was leaking before. It is now rebuilt (followed the manual) and seems to be working correctly and I even double checked I put it together correctly. If I keep the primer bulb pumped it will stay running (used two different newer fuel hoses and bulb). The carb was very clean so cleaned it again just in case. Does it sound like the float needle is sticking since it doesn't always die at the same time? It revs up perfect, idles well and everything in between until it runs out of gas. Any help is appreciated. Thanks.
 
Re: 9.9 Evinrude dies after 20 seconds to 3 minutes, time varies

The primer bulb is a " manual fuel pump "-----------------Therefor you have an issue with the pump or crankcase compression that drives the pump.--------------------Also check the fuel pick-up tube in the fuel tank,=.On plastic tanks they are know to deteriorate with todays fuel.
 
Re: 9.9 Evinrude dies after 20 seconds to 3 minutes, time varies

I have used this fuel tank for over a year on my 18 HP and just used it recently so I don't think that is it. Also have non-ethanol with stabil in it. Is the hole in the middle of the bracket on the fuel pump where the crankcase drives the pump through compression? I am going to try and put the fuel tank up higher too because it is has a pretty long hose (7' or so) and sits about 3.5' feet lower than the motor. If that helps I guess that is stating that the fuel pump isn't getting enough compression, right? Thank you!
 
Re: 9.9 Evinrude dies after 20 seconds to 3 minutes, time varies

Assuming that there is no air/fuel leaks between the fuel pump and the fuel supply....... Borrow a known good fuel pump, install it. Your explanation indicates a pump problem. Your tank hose length is fine.
 
Re: 9.9 Evinrude dies after 20 seconds to 3 minutes, time varies

I have a 9.9 and 15 HP that is still having this issue still. I rebuilt the fuel pump on the 15 HP but they both run about the same time and die which is about 1 minute or so. I have been using the same fuel tank and have even tried a new fuel line, fittings and bulb. I checked compression on both motors and they are both pretty good and also even. Both carbs are clean and one is rebuilt. Do you think it could have something to do with the tank even though the tank works great on my 18 HP? The 9.9 and 15 both run flawless until they die. It slightly helps if I play with the choke but will still eventually die. The lean/rich is out about 1.25-1.75 turns. I guess I can rebuild another fuel pump but this is a weird coincidence don't you think?
 
Re: 9.9 Evinrude dies after 20 seconds to 3 minutes, time varies

I finally got it figured out. I put on a like new fuel pump and the motor ran for about a minute then started dying so I pumped the primer bulb and the kept it primed and ran great after that and didn't die. I swapped that older fuel pump to my other motor and that one runs like a top too once that primer bulb stayed primed. Looks like I will be buying a new primer bulb. Thanks!
 
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