1983 40 hp mariner dies when put into gear. Found water fouling in lower unit.

[ploverkilla]

1983 40 hp mariner. started dying when I put it in gear or would put in gear and then it would lag a bit and suddenly take off. I thought it is a fuel line leak but everything looks ok at the tank and line. I haven't looked to much at the fuel lines in the motor itself. The lag to get going was normal and I just thought I was sucking air some where and I ignored the issue because it still ran. As of this weekend it started dying every time I put it in gear and I had to get the tow of shame back to the dock. I checked the lower unit gear oil and it was grey with obvious signs of water intrusion. Would this cause it to die when put in gear? I check the lower unit oil regularly and it was fine 2 trips ago so I know there is more going on then just the lower unit oil being fouled. The issue was there prior to the lower unit problem but now it seems to be down for the count. I am changing the gear oil today. Any advice to get this thing going again nwithout dying.

 

[chrome dome]

Re: 1983 40 hp mariner dies when put into gear. Found water fouling in lower unit.

not going to be caused by your LU problem
compression test the engine
clean carby
check fuel pump/ lines for leaks etc

at the very least you will need a new seal on the LU, probably drain plug seals as well

 

[ploverkilla]

Re: 1983 40 hp mariner dies when put into gear. Found water fouling in lower unit.

Thanks for the info. Now that I think about it the bulb on the fuel line wasn't staying firm after pumping it. Is this a fuel pump issue? How do I trouble shoot the fuel pump and if it is bad what do I need to replace inside?