1976 mercury 650 3 cylinders keeps slowing down

F

fishnchips2

Recruit
Joined
Aug 8, 2010
Messages
2
can anyone help me figure out why my 1976 mercury 65hp slows down when running in full throttle for about 5 to 10 minutes. ive cleaned out the carbs replaced all fuel lines and filter and changed the plugs. it flys and runs great for the first 5 to 10 minutes while in full throttle and then just rapidly bogs down to probably 5 miles an hour and remains like that. i work on cars and motor cycles but this is my first boat. im thinking that it probably is an ignition or electrical issue, which im not to good with. so if anyone can help me or point me in the right direction, i would greatly appreciate it.

thanx
 
Faztbullet

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,616
Re: 1976 mercury 650 3 cylinders keeps slowing down

Take a timing light with you and when it fails remove cowling and check to see if you have spark on all cylinders. If spark is lost go to CDI website and download troubleshooting manual and test ignition. Is water pump pumping good as it could be overheating?
 
F

fishnchips2

Recruit
Joined
Aug 8, 2010
Messages
2
Re: 1976 mercury 650 3 cylinders keeps slowing down

ive also changed the water pump just 2 months ago. where can i find this cdi web page. i thought i would read up on it.i havnt checked the spark yet but as soon as ido ill keep you posted
 
You must log in or register to reply here.
Top