Surging at half throttle

BBetthauser

Cadet
Joined
Jul 19, 2016
Messages
6
Boat fires up fine and idled great. But once it get up to almost plane af half throttle it starts surging hard. I thought bad fuel so drained the whole tank started fresh, replaced the plugs and wires cleaned the air flow and put a new water fuel separator on it. It did have a melted exhaust flap that was still working but replaced. Had it in 2 separate shops with excellent history of repair but even they couldnt figure it out. Thinking possibly electronic now. Any ideas if this has ever happened to anyone else before?
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,401
Assuming its a Mercruiser because its in this section, but what motor, year , serial number?
Need something otherwise it might be a chain saw :rolleyes:
 

BBetthauser

Cadet
Joined
Jul 19, 2016
Messages
6
Whoops thought that Info was in there when I wrote it out. It's a 1995 four winns with a 5.0 cobra inboard. 220 horizon. Serial number I dont have at the moment.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
... cobra inboard. ...

Shouldn't you be in the OMC sub-forum?

If it is an OMC Cobra, let us know, and we'll move it over there.

Chris........
iboats moderator.

EDIT: Just found your other post, in the OMC section, on the same subject... As it's an older thread, I will leave the 2 separate. I have now moved this across.
 
Last edited:

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,012
Ayuh,..... Carbed, or Efi,..??

Surgin' is usually a fuel delivery issue,....
 
Top