Merc 50hp brownband -gremlins

[Tim Fawcett]

I have recently aquired this motor and it runs sporadically. Sometimes peaks OK other times won't rev and holds back as if suffering fuel starvation or running on fewer cylinders. Plugs OK - new fuel tank using 50:1 - new fuel line - carbs checked and jets cleaned. Any ideas? Tim

 

[tmcalavy]

Re: Merc 50hp brownband -gremlins

You need to find the key to off-peak performance. Does the fuel bulb stay firm? If it gets soft when the prob occurs you have a prob between the tank and the carbs. Check spark when it seems to be running on fewer cylinders. Pull the plug wires one at a time...if pulling the wire doesn't affect how it runs it may be dropping that wire/cylinder under load. Post your model/serial number so you can ID the year. Then find a factory service manual for it if you intend to keep it and run it.