Fuel delivery problem 200HP Mercury

[jdupree]

I have a 1992 Mercury 200HP Offshore. You can start it up cold and it will run all day long at whatever speed you desire. Once it is warm and you cut it off for 10-15 minutes when you try and re-start it will run for about 15 sec and then cut off. At this point the primer bulb is "limp". I have noticed that when it starts to die I can pump the bulb and it will "perk" back up and continue to run. It seems like once you cut the motor off and let it sit that the primer bulb will go limp and loose the gas that is in there.

My first thought was pickup tube but I replaced my tank last year and installed new pickup, hoses, and primer bulb. Could these be the symptoms of a fuel pump?

Any thoughts or experiences with similar problems would be appreciated.

 

[j_martin]

Re: Fuel delivery problem 200HP Mercury

I have a 1992 Mercury 200HP Offshore. You can start it up cold and it will run all day long at whatever speed you desire. Once it is warm and you cut it off for 10-15 minutes when you try and re-start it will run for about 15 sec and then cut off. At this point the primer bulb is "limp". I have noticed that when it starts to die I can pump the bulb and it will "perk" back up and continue to run. It seems like once you cut the motor off and let it sit that the primer bulb will go limp and loose the gas that is in there.

My first thought was pickup tube but I replaced my tank last year and installed new pickup, hoses, and primer bulb. Could these be the symptoms of a fuel pump?

Any thoughts or experiences with similar problems would be appreciated.

I'm assuming it's a carb motor. The fuel pump could be on it's last leg. It's about a 25 buck kit and an hour to throw it in, unless you know what you're doing, then it's about ten minutes.

It's normal for the bulb to go soft, as you are sucking fuel through it. It should not collapse, as that indicates excessive vacuum in the fuel line.

I would throw in a fuel pump kit and try it. If you are still having trouble, put a piece of clear line (temporarily) between the primer bulb and the engine, and observe it when you're having trouble. Any bubbles indicate an air leak.

hope it helps
John

 

[j_martin]

Re: Fuel delivery problem 200HP Mercury

A second thought.

If you can pump the bulb, and it continues to run and keep running normally without further ado,

It could be a combination of bad check valve in the primer bulb, and a small leak anywhere from the primer bulb to the carbs allowing the fuel to fall back down the fuel supply tube after shutdown.

hope it helps
John

 

[jdupree]

Re: Fuel delivery problem 200HP Mercury

Thanks for the tips j martin. I was planning to go ahead with the fuel pump kit. Might go ahead and replace the primer bulb while I am at it.

 

[j_martin]

Re: Fuel delivery problem 200HP Mercury

Thanks for the tips j martin. I was planning to go ahead with the fuel pump kit. Might go ahead and replace the primer bulb while I am at it.

Be sure it's a mercury bulb and hose kit. The aftermarket stuff isn't up to delivering the kind of fuel flow that engine needs.
been there, done that.

John

 

[jdupree]

Re: Fuel delivery problem 200HP Mercury

Be sure it's a mercury bulb and hose kit. The aftermarket stuff isn't up to delivering the kind of fuel flow that engine needs.
been there, done that.

John

As a matter of fact, the primer bulb is a Moeller from Boater's World. That could be a problem???? Come to think of it, this problem might have started when I replaced the primer bulb when I replaced the tank. Thanks!

 

[j_martin]

Re: Fuel delivery problem 200HP Mercury

As a matter of fact, the primer bulb is a Moeller from Boater's World. That could be a problem???? Come to think of it, this problem might have started when I replaced the primer bulb when I replaced the tank. Thanks!

BINGO!!!

Throw in the pump kit anyway.

John