1988 75 horse Mariner still wont run PLEASE HELP!!

[starkyb]

I just pulled the #2 carb on my motor because I couldnt get any power out of my #2 cylinder. After alot of cranking I was able to get it going. I pulled the wire off of #2 plug and there was absolutely no change in how it ran. I know I have spark and compression on that cylinder. The reed valves are good and the carb is clean. I am totally dumfounded at this point. What else could it be?

 

[MH Hawker]

Re: 1988 75 horse Mariner still wont run PLEASE HELP!!

Is it getting spark and or fuel. If the plug is wet then its getting fuel. Run a coil test if no spark. If the plug is dry put a bit of fuel into the cylinder.

 

[starkyb]

Re: 1988 75 horse Mariner still wont run PLEASE HELP!!

The spark is good but it's the fuel going in that seems to be the problem. I can't understand how it's not getting in the combustion chamber. The carb is squeaky clean and the float is functioning properly. The reeds look new but if that cylinder was working wouldn't it change the performance if I pulled the wire while it was running?

 

[MH Hawker]

Re: 1988 75 horse Mariner still wont run PLEASE HELP!!

If it isn't getting fuel it wont fire and it would make no difference as to how its running, so its simple, If their is fuel in the carb bowl, if their isnt then its a delivery problem you have more than one carb so that sort of rules out the fuel pump and delivery lines, it their is then the carb is stopped up. Take the line lose that feeds that carb and give the ball a pump, if its squirts out then you will know.

 

[brnschoneck]

Re: 1988 75 horse Mariner still wont run PLEASE HELP!!

you can also turn it over with a plug out and fuel line to carb off and make sure pump is pu ping fuel ?? also make sure fuel tank is vented properyl I had this happen before when i put fuel cap on somehow closed the vent screw ??? Just a thought ???

 

[starkyb]

Re: 1988 75 horse Mariner still wont run PLEASE HELP!!

Update on my problem. Took the boat out today and was able to get it started but still ran rough. After disconnecting the fuel line it smoothed out. I called the master mechanic in town and he told me that it was probably the fuel pump. He said that if I take off the line from pump to the block and squeeze the primer bulb and fuel comes out than my diaphragm is ruptured. Sure enough gas came out of that hose. That is a vacuum hose. Bought a kit and I am about to start on it now. Thanks for the help guys!

 

[starkyb]

Re: 1988 75 horse Mariner still wont run PLEASE HELP!!

Problem solved. She is purring like a kitten and roaring like a lion. The fuel pump was assembled incorrectly. He has the diaphragm and gasket flipped flopped. The diagram that came with the kit was wrong. I realized that after I put it together and it was still leaking. When I analized it I tried switching it and it worked. Going to put on the water tomorrow