Omc cobra 91

"I've replaced the geacase

"I've replaced the geacase assemblies and can't locate replacement nuts to secure the upper gearcase to the transom, can anybody tell me where I can get these from? Also I am getting a "beep" when the engine is running, I am showing no oil pressure or water temp. I asume that my sender units are bad..is this what's causing the alarm?

Thanks"

"You can order them from this

"You can order them from this link, see item # 65, you'll need 6.

http://www.dougrussell.com/partscatalog/volvo_omc/index.cfm?fuseaction=comp&grou p=976&GroupList=954,955,956,957,958,959,960,961,962,963,967,966,968,969,970,971, 972,973,974,975,976

For the alarm, is it a steady beep or a pulse? OMC did have kit that waqs installed on some engines and of course there aftermarket kits that basically add 2 switches for an alarm. One is a NO OIL pressure switch and the other is an HIGH TEMP switch. These are in addition to your normal sending units that provide a signal to your gauges. Before you start replacing senders check for 12v on the gauges themselves. Does the beep start right away or after it's been running for a while? What size engine is this and is the drive a King Cobra or just a regular Cobra?"

"It's a Ford 5.0 V8, the a

"It's a Ford 5.0 V8, the alarm starts right away, the actual alarm is situated behind the switch panel on a Sundowner 205, and presumably I have to check the 12v on the signal connection on the gage?"

"No for the gauges you will ha

"No for the gauges you will have at least 3 wires on the back, more if it has internal lighting (most do) You will have a 12v, a ground and a S for the sender. The sender is actually a variable resistor to ground so if you meter that you won't find 12v. It sounds like they may have wired up the OMC alarm kit on yours, normally if it goes off as soon as you turn on the key it's the no oil pressure but normally turns off as soon as the oil pressure builds a little bit. I've included 2 pics below (you may have to enlarge) the first one is 1991 5.0 intake diagram. See items 21 and 54, 21 is the Over Temp switch and 54 is the temperature sender for the gauge. In the other which shows a 1991 crankcase see items 61 and 68, 61 is the oil pressure sender for the gauge and 68 is the no oil pressure switch. I believe those switches will just have a single tan wire on them and they are usually wired together so unfortunately when the alarm goes off you don't know which one but normally you won't get an over temp alarm right away unless it's false. Find the oil pressure switch, start the engine and pull the tan wire off and see if the alarm goes off, if not then try the over temp switch.

1991 5.0 intake"">
1991 5.0 Crankcase