OMC Cobra Water Pump Drain Screw ?

When getting my 1987 OMC 4.3 ready for winter, I unscrewed a drain plug in the center of the port side of the upper gearcase housing. This seems to drain the water pump area.<br /><br />When I went to replace the screw, I found that there were no threads there, and that it had been glued in place! There is only a hard rubber ring in that hole, with no threads. The drain screw I removed looks like a typical one for a lower gearcase.<br /><br />Looked in my 1988 OMC 4.3 parts catalog (one year newer) and they only show the starboard side with no mention of that drain screw.<br /><br />OK - I'm stumped. What kind of a plug should go in that water pump drain hole? Anybody have a picture or part number?

Re: OMC Cobra Water Pump Drain Screw ?

As you found out that screw is not to be taken out you are not the first person to remove that screw. If you take the drive off you can find the backing plate that screw is held to. You need to glue it in with weather adhesive (yellow death) is what I call it. If you cant find the backing it can be ordered but it isnt in the parts book. When you put it back together it has to be weather tight. If it leaks the water pump will suck air and you will have a cooling issue. I always seal that screw if the cobra sticker is missing. vinney.

Re: OMC Cobra Water Pump Drain Screw ?

Vinney,<br /><br />I was following the instructions in the Clymer OMC Cobra Stern Drive Shop Manual. It says to remove the "water drain plug located on the port side of the pivot housing."<br /><br />Did I get the wrong drain? I didn't notice another drain on that side.<br /><br />Why would Clymer make such a mistake?

Re: OMC Cobra Water Pump Drain Screw ?

There is a drain screw but it is lower down on the upper housing. you need to trim the drive up to see the screw. Make sure you grease the threads when you remove it. That screw you removed is covered with a sticker that has OMC cobra on it. As time goes by that sticker falls off. Im not a big fan of the after market service manuals. I always you the factory manuals. When you pull the drive to get the backing plate you will see the drain screw its lined up with the water tube. The drain screw has an oring on it make sure you dont loose the little oring. Vinney

Re: OMC Cobra Water Pump Drain Screw ?

Vinney,<br /><br />Thanks very much for the advice.<br /><br />Luckily, I am planning to pull the drive next Spring, so getting to the backing plate won't be a major adventure by itself.

Re: OMC Cobra volvo lower unit were do i fill oil

Re: OMC Cobra volvo lower unit were do i fill oil

how do i fill my 96 omc cobra sx volvo lower unit can some one help thank you:redface:

Re: OMC Cobra Water Pump Drain Screw ?

Welcome to Iboats..
You need to start a new thread with your question being this one is 7 years old.
Post the year,make and model of the engine and drive in the new post and the guys will be glad to help you out.