Merc 200 20 hp Running out of fuel PLEASE HELP !!!!!!

[JGra]

Re: Merc 200 20 hp Running out of fuel PLEASE HELP !!!!!!

Yes I had a couple leaks at the tank fitting and some of the lines. I have since replaced everything from the tank valve on the tank to the carburator. No change. The pick up in the fuel tanks is good.

 

[Arkman]

Re: Merc 200 20 hp Running out of fuel PLEASE HELP !!!!!!

JGRA-
You need to quit your job or something so you can stay home and solve your motor problem. I'm eagerly awaiting your solution. You are a few steps ahead of me on my same problem. If you solve it then I dont have to go through the trouble shooting process.

Hope you fix it...SOON!

 

[JGra]

Re: Merc 200 20 hp Running out of fuel PLEASE HELP !!!!!!

I sure wish I could. I spend too much time working on that motor already. My wife made a comment this weekend, does she have to sit in that dam boat in order to spend time with me. I told her that would be a start. That did not go over too well. Anyway, I took the carb back apart ths weekend and cleaned every passage in it. I also readjusted the float level to allow a little more fuel into the carb. I am going to temporally install a clear piece of clear fuel line from the fuel pump to the carb so I can see whats its doing while running. Seems to run good on the hose but I dont want to bring the RPMS up to high on the muffs. I am going to try and take it out one day this week after work and see how it does. If this dont work I think I am going to try a low press electric fuel pump or just get the 12 ga Shotgun out and just be done with it (just kidding). On yours I would rebuild the fuel pump. The kit is only about $6.00. I bought mine off of e-bay and that was one of the first things I had to do to even get mine to idle without cutting off. I will keep you informed.

 

[fred's]

Re: Merc 200 20 hp Running out of fuel PLEASE HELP !!!!!!

I would go ahead and rebuild it. There is nothing to it and it might fix your problem. Mine was really bad before I rebuild it. I could not keep it running for any lenght of time. Now it idles great and runs great to about 1/2 throttle. Just need to get past this one problem and the motor should be good to go.

did cab & pump twice all new lines, still have to pump the bulb to keep it going

 

[Arkman]

Re: Merc 200 20 hp Running out of fuel PLEASE HELP !!!!!!

Did you replace the bulb itself? How about the gas tank? Is then vent open? I would check the line inside the gas tank, I had an issue with that as well. Good luck fred.

 

[SS338]

Re: Merc 200 20 hp Running out of fuel PLEASE HELP !!!!!!

Take the outlet line that goes to the carb off and crank the engine. There should be fuel spitting out of it if the pump is working. If there is no fuel, put a little fuel in a can or an oil bottle and put the intake line on the fuel pump into the fuel and crank the engine it should start to draw the fuel in just a few cranks if the pump is good. If not you have an obstruction or a leak somewhere on the intake side. If it pumps fuel, the problem is in the carb. I have seen fuel systems that will leak air in, but not leak fuel out. This will maybe give you a starting point as to what is wrong.

 

[fred's]

Re: Merc 200 20 hp Running out of fuel PLEASE HELP !!!!!!

Take the outlet line that goes to the carb off and crank the engine. There should be fuel spitting out of it if the pump is working. If there is no fuel, put a little fuel in a can or an oil bottle and put the intake line on the fuel pump into the fuel and crank the engine it should start to draw the fuel in just a few cranks if the pump is good. If not you have an obstruction or a leak somewhere on the intake side. If it pumps fuel, the problem is in the carb. I have seen fuel systems that will leak air in, but not leak fuel out. This will maybe give you a starting point as to what is wrong.

my fuel line goes to the pump, conected to the carb?

 

[fred's]

Re: Merc 200 20 hp Running out of fuel PLEASE HELP !!!!!!

Yes I had a couple leaks at the tank fitting and some of the lines. I have since replaced everything from the tank valve on the tank to the carburator. No change. The pick up in the fuel tanks is good.

same here tried two tanks new lines nothing worked

 

[corm]

Re: Merc 200 20 hp Running out of fuel PLEASE HELP !!!!!!

JGra said. I pulled the 2 lines going to the fuel pump from the power head and the fuel pump is getting good pulse pressure to the fuel pump. Unless ther is something wrong with the fuel pump that a kit is not fixing I am out of answers.I am going to take it out

Hi,
Here is a shot list of things I've seen.

The pump crankcase pressure lines kink and reduce the pressure to the diaphram when the pump is installed. Also they become soft and bulge rather than flow the pressure to the diaphram.

The check valves in the pump body could be bad.

The male fuel connector on the engine is wore so it pulls air. Look at the latch pins. They wear down from vibration on the back side. This allows the hose connector to back out a little so the dual o-rings do not seal up good Also check the anti siphon valve o-ring in it. It is on the black rod you see sticking out, spring loaded from the back side.

I have seen the reed block bearing become so worn that it allows the crankcase pressure to go back n forth between the cylinders cutting down the pressure to the fuel pump diaphram.

I have seen a bad bottom seal cause the problem too.

I think you have covered everything else
The electric low pressure pump will work if your battery stays up.
The pump Dia you bought off e bay, was it a Mercury Marine made kit?
Some after market kits have diaphragm that do not work well.

In this picture http://www.crowleymarine.com/mercury_parts/439/7.cfm
The top metal pump check valves are NLA, the bottom synthetic pump you may be able to get valves for. You may be able to get a whole syn pump from a used parts dealer like twincityoutboard.com, yahoo some there are lots of them. To replace the metal pump with the syn one if that is what you have.

 

[Lion hunter]

Re: Merc 200 20 hp Running out of fuel PLEASE HELP !!!!!!

No offense Fred but you kinda highjacked this thread and it makes it difficult to determine whose problem is being diagnosed.

 

[mmf]

Re: Merc 200 20 hp Running out of fuel PLEASE HELP !!!!!!

take the fuel hose loose at the fitting at the motor, insert a tight fitting 5/16-3/8 bolt into the line and clamp good with a hose clamp. Pump the bulb up till it is hard and walk away, come back in an hour and see if the bulb is still hard, if it is soft your check valve in the bulb is bad or your hose is leaking (sucking air) or you have a crack in the tube that goes from tank top to bottom or leaky fuel tank fitting.

 

[fred's]

Re: Merc 200 20 hp Running out of fuel PLEASE HELP !!!!!!

No offense Fred but you kinda highjacked this thread and it makes it difficult to determine whose problem is being diagnosed.

Sorry, just thought we were doing the same thing to the same motors and getting the same results, I've posted a similar tread and not gotten any responses, I was hoping we could help each other out.
I don't see any deference from what we've done, from what I see we've done the exact same thing to the same motor and gotten the same result, it's sure helped me knowing, it must be something we haven't done.
I'll back off
JGra sorry wasn't trying to steal your post
later