mercury
 

hello everyone, i have a question about a 1977 mercury outboard 6 cylinders,2 stroke motor. when the engine cover is on, the motor wont start or run, but as soon as the cover is off, the motor runs fine. i have changed the spark plugs and its still doing the same thing. also, when it reaches 40 mph, it stops. so i have to push the throttle back and it starts again. any help would be appreciated. thanks

Re: mercury
 

Not really enough info. to be much help here. In 1977 Merc. made both in-line and V-6's. What exactly do you have there? -- What H.P.? --- jp

Re: mercury
 

Exhaust leak in the cowl?

Re: mercury
 

good call, but you'd think it would start the first time while there is still fresh air in there. are your plug wires bad and cowl pushing them up against something causing an arc?

Re: mercury
 

yes, please provide specific information.

What motor is it? Inline 6 motors had steel "wrap" cowlings that can short out electricals. Vee 6 motors have plastic/fiberglass cowls that cannot short electricals (but can push wires to other stuff that will short them).


Then on one hand you say that the motor starts and runs fine with the cover off.
On the other hand you say it stops at 4000rpm and requires a restart. This is not "running fine".

We'd love to help, but you got to be specific.