TinBoats.net
The original aluminum boat site!
Forums
New posts
Search forums
Blog
What's new
New posts
New media
New media comments
Latest activity
Media
New media
New comments
Search media
Members
Current visitors
Log in
Register
What's new
Search
Search
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Boats
Motors
1969 Mercury 7.5 HP repairs
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Help Support TinBoats.net:
This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Message
<blockquote data-quote="JMichael" data-source="post: 276800" data-attributes="member: 7544"><p>I had a 66 model 3.9 merc that had the same 2 issues. I replaced the impeller and rebuilt the fuel pump. The water flowed slightly better but still not quite what I thought it should be. It continued to die unless I kept the bulb pumped. After quite a bit of testing, I discovered the O-ring inside the female connecter (that attaches the line to the engine) had a small nick in it, allowing it to suck just enough air to prevent the pump from being able to do it's job. I replaced the O-ring and never had another fuel problem. I continued to run the motor with what I considered weak water flow up until I sold the motor this spring.</p></blockquote><p></p>
[QUOTE="JMichael, post: 276800, member: 7544"] I had a 66 model 3.9 merc that had the same 2 issues. I replaced the impeller and rebuilt the fuel pump. The water flowed slightly better but still not quite what I thought it should be. It continued to die unless I kept the bulb pumped. After quite a bit of testing, I discovered the O-ring inside the female connecter (that attaches the line to the engine) had a small nick in it, allowing it to suck just enough air to prevent the pump from being able to do it's job. I replaced the O-ring and never had another fuel problem. I continued to run the motor with what I considered weak water flow up until I sold the motor this spring. [/QUOTE]
Verification
Post reply
Forums
Boats
Motors
1969 Mercury 7.5 HP repairs
Top