89 OMC 5.8L Cobra Stalling Problem

Scurvy Dog

Recruit
Joined
Jul 11, 2003
Messages
4
Hi All-<br /><br />I have a 1989 OMC Cobra that runs smoothly from 0-3000 rpm in neutral, but when in gear (under load) as I approach 2000 rpm, it sputters and stalls (unless I push the throttle quickly through it). It does the same thing as a dethrottle as well. Any thoughts?. It has electroninc ignition.<br /><br />thanks
 

a.d.mobile

Petty Officer 1st Class
Joined
Jul 15, 2002
Messages
326
Re: 89 OMC 5.8L Cobra Stalling Problem

probally a carb problem is it a holly or rochester?
 

Scurvy Dog

Recruit
Joined
Jul 11, 2003
Messages
4
Re: 89 OMC 5.8L Cobra Stalling Problem

The carb is a Holley 4160. I thought it might be a carb problem (the boat sat unused for 2 years) but it also stalls out while throttling down thru that same range (unless I do it slowly).<br /><br />It has electronic ignition.
 

ed hobbs

Seaman
Joined
Jul 19, 2003
Messages
51
Re: 89 OMC 5.8L Cobra Stalling Problem

Aren't Holleys notorious for having a flat spot? Maybe I heard that from a anti-Holley tech.
 

a.d.mobile

Petty Officer 1st Class
Joined
Jul 15, 2002
Messages
326
Re: 89 OMC 5.8L Cobra Stalling Problem

Find a carb shop if you can a holly is a great carb done right but can be a pain if not. if you would try this yourself there is a book out in the auto world the title is (how to build a holly) it covers alot and is worth reading before you do one. omc flat rate is 4.0 on that at a dealer here they charge 75.00 hr that is 300.00 and a good kit with power valve secondary spring and diaphram will cost a 100.00 Maybe check new also. If you find a carb shop they probaly wont hit to hard.
 

chris in va

Chief Petty Officer
Joined
May 4, 2003
Messages
410
Re: 89 OMC 5.8L Cobra Stalling Problem

I had the same problem on my 302/Holley. Turns out the flat metal spring inside the bowl that regulates how much fuel gets in past the needle was bent down, and the bowl would get sucked dry before the needle would open. <br /><br />I would start there. Very easy thing to check.
 
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