15hp Primer/Injector and carb question.

[hardwater fisherman]

My nephew has a what I believe is a 1994 15hp. Serial number G022821. He has had starting and running problems. This morning he had problems starting and when it did start he had to throttle up quickly to keep it running. Then he went a few hundred yards and he said it bogged down and died. He texted me and I came from the other end of the lake and towed him back to the launch. From just a lakeside test it appears to have good spark. I tried to get it going and I could only get it to sputter but not start. I then noticed when pulling the primer gas would spray out a little hole in the metal diaphragm cover. I think this would effect starting, but would this also keep it from running? Would this indicate the diaphragm is damaged? Thanks for any help in advance.

 

[flyingscott]

Yes if the primer diaphram is cracked it will leak and cause the engine to flood. I think you have 2 problems a bad diaphragm and the check ball in the primer may be pushed into the spring and not sealing anymore.

 

[hardwater fisherman]

Okay thanks. I already told him to order a rebuild kit for the primer. I was looking at the online manual and it says that if the check ball is not seated then it could cause excessive smoke at idle. After reading that I remember him telling me that last weekend he had problems and it did smoke more than normal. I think your right about the flooding also because he said that when he tilted the motor up gas was coming out the throat of the carb. I had very hard time to convince him that there is no choke on the motor but it is a primer. So the whole time he is trying to start it the primer was fully pulled out.

 

[flyingscott]

To start that motor you turn the knob all the way to the right THEN pull out. When it starts wait a couple of seconds then push the knob back in. When the idle picks up start backing the knob off to the left all the way. Get the whole carb kit for that motor that way you can get a new needle and seat and fuel pump gaskets and diaphragm. When you tilt the motor up it is normal for gas to run out.

 

[hardwater fisherman]

Thanks. First I told him to buy a complete kit and he does not want to even pay for the primer kit. I try to help him but he does not understand that there is always going to be something to fix or maintain. The boat and motor belonged to his girlfriends father and he has been using it for more than 8years and he has done nothing. I had to shame him into changing the gear oil. And he still has not touched the water pump. The water pump is working but for how long I dont know. I am sure it has not been changed for a decade or more. And to top it all of the motor came off a pontoon boat that her father also owned. They sold the pontoon and kept the long shaft motor and he has been using it on a 15 inch transom.

 

[hardwater fisherman]

You were correct the check ball was stuck in the spring and the diaphragm was in bad shape. He bought a complete kit and it is running good again. Thanks