Logo
FULL SITE MENU

1980 25 hp mercury problem

B

bakenast

New member
I forgot exact model but it’s 1980s 25hp between model# 5705532 - 6416712 since part# are the same Anyways I can’t get it to stay running I can get it to start with choke on and will run if I keep giving it gas /w choke on but then just dies once I turn off choke , I rebuilt the carb with kit, and also tried a 20hp carb I bought offline that fit it but it does the exact same thing. I replaced plugs/coils/wires I have no idea what else to check

Also

i replaced my water pump I have it set on key shaft correctly and new seals but it will not pump any water just steam I blew air through lines and can’t find any clogs, I am using a 55 gallon drum of water. Does the water level need to be level with the water pump to work or just cover the water inlet on bottom?? Thanks for any help
 
That motor has been known to have reed assembly sealing problems. Pull the carb and reed plate behind it and check the rubber gasket to make sure it's sealing properly.

On the water pumping problem, it yours has a thermostat it may not be opening yet. Get her running first and then worry about the water pumping issues.

Jeff
 
..."Is the carb base gasket on correctly? "

Good point! The gasket behind the carb has a hole in it that MUST line up correctly or the fuel pump can't operate. Check it out!

Jeff
 
Back
Top