28hp problems

[quackaddict1]

Well, I thought I had my problems licked, but I got kicked in the face this AM when I took my boat out to go fishing. I have a 95 28hp Johnson. I have installed a carb kit, a fuel pump kit, new line from the fuel pump, two intake gaskets, a primer cover, and the motor still acts like its starved for fuel. I have 120 and 117 for compression in each hole. It ran great in the tank thursday night, idled, wound up, everything. Today it acted like it was getting no fuel, It would start, but not get past the idle, would wind up every now and then just die. After a period it just quit even starting. Do I still have a head leak? The fuel line and tank are relatively old, could anything here cause problems? The primer ball stayed hard the entire time and all the screens were clear of obstructions. Any ideas?

 

[samo_ott]

Re: 28hp problems

Sounds like it might be running on one cylinder? Do you get a good spark on each plug?

What happens if you spray 50:1 pre mix in the carb when it is balking? If it clears up briefly then it's a fuel issue.

 

[tashasdaddy]

Re: 28hp problems

when you did your carbs, did you do all of this? http://forums.iboats.com/showthread.php?t=244013

 

[quackaddict1]

Re: 28hp problems

There is only one carb on this motor, and yes I did as the thread suggests. I don't believe the motor is hitting on just one because when it does run it it runs smoothly, actually idled nice for a little bit at half choke setting. Tomorrow I am going to replace the fuel lines and tank and see what that does.

 

[quackaddict1]

Re: 28hp problems

Another thought, could a pump be put together incorrectly so that it pumps as it should at low RPM but then fails to pump enough fuel at WOT? When I rebuilt it it would pump a steady continuous flow under the starters power.